Azure Container Apps Sandboxes (Preview): Giving AI Agents a Safe Place to Work
Co-written by Nikoloz Buligini, Front End Developer at Templafy, and Jan Kalis, Azure Container Apps Sandboxes, Core AI, Microsoft Every team building with multi-tenant AI agent platforms hits the same wall. The agent is smart enough to read your code, reason about a bug, and propose a fix. But the moment it needs to take an action - clone a repo, install tooling, run a command, hit an internal endpoint - you have to answer some uncomfortable questions: where does it run, what permissions does it have and what can it access? Run it on your own infrastructure and inherit the blast radius. Give it broad network access and you have handed an autonomous process the keys to your environment. Lock it down too hard and the agent cannot do its job. This is exactly the problem Azure Container Apps Sandboxes was built to solve. And it is exactly the problem the team at Templafy solved in production. This post walks through what Sandboxes are, the features that make them a good fit for agentic workloads and how Templafy put ACA Sandboxes to work. What are Azure Container Apps Sandboxes? Azure Container Apps Sandboxes (Preview) are secure, isolated compute environments that start in seconds, scale to thousands, and do not charge you for compute while stopped. Each sandbox runs inside its own hardware-isolated microVM, fully separated from the host, the platform, and every other sandbox. Bring your own container image or use an included one, and Sandboxes handle provisioning, isolation, and lifecycle. This is the same compute fabric behind products like Cloud sandboxes in GitHub Copilot, Foundry Hosted Agents, and Azure Container Apps Express, and now you can build directly on it. For platform builders, that means enterprise-grade, multi-tenant isolation as a building block you would otherwise spend years creating. For AI agents, a sandbox becomes a self-configurable tool: spin up a fresh environment in seconds, run untrusted code, compile a project, or explore a codebase, then throw it away. On one side you empower humans to build platforms. On the other you empower agents to extend their own capabilities. The features that make Sandboxes fit agentic work A fast microVM is table stakes. What makes Sandboxes practical for real agent workloads is the control around them. Snapshots capture a fully configured environment and resume from it, ideal for long-running tasks or cloning setups. Egress controls declare exactly what a sandbox may reach, so an agent can pull from source control and package registries but nothing you did not approve. Managed identities authenticate to Azure with no secrets in the image. Automatic suspend and resume map cleanly onto how conversational agents behave, warming back up with full context when a conversation continues. Ports give your orchestrator a channel to a long-running agent process inside the sandbox. Two newer capabilities go further: virtual network integration puts an agent workspace inside your own Azure VNet with access to private endpoints, and bring your own storage lets data and artifacts outlive a session under your compliance rules. Together these turn a fast disposable VM into something you can hand to an autonomous agent in production. Which brings us to Templafy. How Templafy uses Sandboxes, in their own words The following section is written by Nikoloz, Front End Developer at Templafy. At Templafy we built an AI agent that helps our teams by doing longer-running source-code exploration on their behalf. Someone asks a question in a Slack thread, and behind the scenes the agent needs a real, isolated workspace where it can clone repositories, run tooling, and dig through code without touching anything it should not. It started as an engineer-facing tool for deep technical questions, but we recently opened it up to our product team for questions about undocumented product behavior. There, the agent first checks our Help Center through Azure AI Search with no sandbox required and only spins up a sandbox to explore the code when the docs come up short. Since these users aren't engineers, we summarize what the exploration finds into something more approachable. Funnily enough, the product team has been using it more than engineering does, and the feedback since launch has been great. We needed strong isolation, fast startup, and tight control over what each workspace could reach. Azure Container Apps Sandboxes gave us exactly that. We were sold on the model early enough that we built our own TypeScript SDK for Sandboxes before there was an official one, so we could drive the whole lifecycle from our Node stack. Here is what happens when the AI decides to start a workflow for a Slack thread: Create a sandbox from the public node-24 image. Install Git and other development tools. Clone our repositories and configure OpenCode. Restrict egress to only the Azure DevOps, package registry, and service endpoints the agent actually needs. Expose a port used to communicate with the agent runtime. Create and reuse snapshots so we do not repeat the bootstrap process on every run. Associate successful sessions with their Slack threads for a short period, so users can make follow-up requests against the same warm workspace. Stop or suspend idle sandboxes and resume them when a conversation continues. Delete failed or expired sessions. To do all of this we lean on the SDK for the full surface area: sandbox lifecycle operations, command execution, files, snapshots, ports, egress policies, public disk-image inspection, and sandbox state. Two features carry most of the weight for us. The first is restricted egress. Our agent is autonomous and works with our source code, so we are not comfortable letting it talk to the open internet. Declaring a narrow allow-list of endpoints means the workspace can do its job and nothing more, and that control is what let us ship this with confidence. The second is snapshots. Cloning repositories and configuring the toolchain is not free and doing it on every Slack message would make the agent feel slow. With snapshots we pay that cost once and resume from a ready-to-work state, so follow-ups in a thread start fast. This is only the first workflow. We are already looking at background investigations using Application Insights and eventually letting the agent open pull requests for quick bug fixes. The same isolated-workspace pattern extends cleanly to all of it. Who this is for If you are building an AI agent that needs to run code, explore a repository, or reach into your systems, and you have been nervous about where that runs, ACA Sandboxes is for you. You do not have to choose between a capable agent and a safe one. Give it a hardware-isolated workspace, declare exactly what it can touch, snapshot the setup, and let it work. Templafy went from "how do we let an agent safely explore our source code" to a production workflow running out of Slack threads, on infrastructure they controlled end to end. The building blocks are the same ones you can pick up today. Next steps Create your first sandbox - https://sandboxes.azure.com/ Explore Azure Container Apps Sandboxes documentation - https://sandboxes.azure.com/docs/sandboxes/ Start with Azure Container Apps Sandboxes samples - https://github.com/azure-samples/azure-container-apps-sandboxes/Zero Ops: Agents Operate, Humans Govern
How to design, build, and grow an agentic operations practice — and what becomes possible once you do. A note on scope: the patterns in this guide apply to any agentic operations platform. The specifics — the pricing model, the built-in capabilities, the primitives named throughout — are Azure SRE Agent. Where something is a property of the product rather than a universal truth, it’s called out. Remember when? Remember the 3am page? The one where you sat on the edge of the bed with a laptop balanced on your knees, hunting through six dashboards to work out whether the thing that woke you was even real. Half the time it wasn’t. Remember the cost review? Somebody exports a month of billing to a spreadsheet, three engineers spend a fortnight arguing about which resources are actually orphaned, and by the time you’ve agreed on a plan the next month’s bill has already landed. Remember the zero-day? The all-hands marathon. Two days of people cancelling everything, tracing which services pulled the affected package, hand-patching in an order nobody had time to write down. And remember the CVE backlog — the one everyone knows about, the one that only ever grows, because triaging it properly would take a team you don’t have? None of that was a failure of effort. It was the operating model. For decades it looked like this: humans operated, software assisted. We built dashboards, alerts, runbooks, automation scripts, and eventually copilots — and through every one of those advances, the human was still the operator. That’s the part that’s changing. And it’s genuinely good news. Agents operate. Humans govern. That’s Zero Ops. And the best part is you don’t have to invent it — the path is already well-worn. The five things worth knowing before you start Everything below comes from building and running agentic operations at scale. If you read nothing else, read these. 1. Zero Ops is the destination — and it doesn’t mean zero humans. It means removing operations from humans. People don’t disappear; they move up the stack. They set the intent, govern the system, and validate outcomes. Nobody’s job becomes “watch the dashboard” ever again. 2. The model is not the moat. This was the biggest surprise. The model matters less every year. You can swap models. What you cannot swap is the context and governance wrapped around them. That’s the durable asset you’re building. 3. Context creates intelligence. Agents become genuinely useful the moment they’re grounded in reality — your source code, your live telemetry, your institutional knowledge, your incident history, and the skills and tools to act on all of it. Swap the model and the system still works. Swap the context and it stops being useful. 4. Governance creates trust. Enterprises don’t trust intelligence. Enterprises trust controls. Identity, audit, evals, rollback, evidence. Governance is what earns the right to automate — and it’s liberating rather than restricting, because it’s what lets you say yes. 5. Metrics create permission. Nobody should trust an agent because a demo looked impressive. Trust comes from numbers you can run yourself. If only the vendor can produce the number, it’s marketing. If you can query it, it’s a metric. The climb, and the one thing that changes at each rung Here’s the elegant part. As an agent matures, the thing that changes isn’t how clever it is. It’s what the human reviews. Rung What the agent does What the human reviews Crawl Suggests. A human still does the work. Their own work Walk Does the work one step at a time, asking before each action. Every step Run Completes whole tasks and hands back a change to approve. The diff Fly Fixes, deploys to test, validates the outcome itself, posts the evidence. The outcome And between Run and Fly sits the review wall. When an agent produces hundreds of changes a month, reviewing someone else’s diff is nearly as hard as writing it yourself. That’s where teams plateau — not because the agent isn’t capable, but because the humans became the bottleneck. Fly is how you get past it: you move the unit of human review from the diff to the outcome. Hold that thought — we’ll come back to it, because it’s the most exciting part of the whole journey. Getting there is a design problem before it’s a technology one. Agents that climb were built to climb. So let’s start where every one of them starts — how you scope it, what you teach it, and what you connect it to. Part One — Designing your agent Before you start: what you’ll want in place The good news is that this list is short, and you almost certainly have most of it already. There’s no platform to stand up first. Diagnostic logs turned on for the services you care about. An agent can only reason about what your system actually emits. Telemetry the agent can query. It doesn’t need to live in one place — most estates have it spread across several platforms, and that’s completely fine. What matters is that each of those places is reachable and queryable. This is what turns “something is wrong” into “here’s why.” Read access to the sources that hold the answers — your subscriptions, your repositories, your incident history, your ticketing system. An identity for the agent, with permissions scoped the way you’d scope a new team member’s on day one. A repository for agent artifacts. Skills, custom agents and tool definitions are production code. They deserve version control from the first one. That’s it. Nothing here is agent-specific — it’s the same hygiene that makes a system operable by humans. If your on-call engineer can answer a question at 3am, your agent can too. Step 1: Scope it — how many agents do you actually need? Good news first: fewer than you think. Teams often assume one agent per team, and that’s usually wrong. Five considerations decide it: 1. Fixed cost. Every Azure SRE Agent carries a small baseline charge just for existing — think of it as keeping the lights on so the agent is ready the instant something happens. That means consolidating where you can is genuinely good hygiene: fewer agents, each with a clear job, means every dollar goes toward outcomes rather than idle capacity. 2. Context. This is the big one. An agent is powerful because it holds a complete picture of a system. Split one application’s context across two agents and you’ve halved what each of them knows — usually the half that mattered. Don’t split an app’s context. 3. Data residency at rest. If data legally cannot leave a geography, that’s a boundary, and it’s a real one. Separate agent, separate region. 4. Team and organisational access boundaries. Genuinely different permission sets and genuinely different blast radius deserve genuinely different agents — each with its own identity, so least-privilege actually means something. 5. At least one dev agent. Always keep a non-production agent to test changes before they touch prod. Same reason you have a staging environment. That’s the whole list. Everything else, consolidate. Ideally, this is what it looks like. A single agent per application or product module — never splitting one across two. Explicit production and test agents. A regional agent wherever residency genuinely demands one. Every split maps to one of the five considerations above. The one thing to protect in every split decision is context. When two agents need to reason about the same problem, each one only has half the picture. If you absolutely must split context — say your org structure or access boundaries require it — plan for those agents to talk to each other so the full context is still reachable. Multiple patterns work. A dedicated infrastructure team that manages AKS clusters and only cares about the upkeep of that infrastructure? A single agent scoped to those resources makes perfect sense — they have a clear domain, a clear boundary, and a clear job. An application team whose service depends on a database? Give that application’s agent access to the database rather than standing up a second agent and splitting the problem’s context across two. There’s no single right layout — the principle is: keep the context of the problems you’re trying to solve together. Step 2: Teach it — context is king This is where the magic actually comes from, and it’s the step most worth over-investing in. Your agent needs five kinds of context: Source code — what the system actually does Production telemetry — what it’s doing right now Institutional knowledge — how your team really operates Previous incidents — what broke before, and why Skills and tools — how to act on any of it Connect the first two and you have a competent log reader. Add the middle two and it starts sounding like someone who’s worked on your team for a year. How you actually bring context in: Connect the real sources — subscriptions and their telemetry, your repositories, your incident history, your ticketing system. Knowledge as markdown in a repo. This is the pattern that works best. LLMs are exceptionally good with markdown files, and putting your knowledge in a connected repository means it’s version-controlled, reviewable, and — critically — updatable by the agent itself. Your scheduled tasks can automatically improve these files as the agent learns, closing the loop between insight and artifact. Connect external knowledge via MCP. If your team’s knowledge lives in Confluence, SharePoint, or another platform, connect it as an MCP server rather than migrating it. The agent queries it at runtime. Upload documents. Architecture diagrams, architecture decision records, design docs, onboarding guides. It reads all of it. Just talk to it. This is the underrated one. Tell it how your system works. Explain that “the blue cluster” means the EU stamp, that Tuesday deploys are riskier, that this alert is always noise before 8am. Ask it to summarise your architecture back to you — where it’s wrong, you’ve found a context gap, and you can fill it on the spot. One thing to be deliberate about: don’t dump everything. If you’ve accumulated years of documentation, runbooks, and tribal knowledge, resist the urge to pour all of it in on day one. Garbage in, garbage out. The agent will work with whatever you give it, and outdated or contradictory knowledge makes it worse, not better. Curate intentionally. Start with the knowledge that matters for the scenarios you’re tackling first, make sure it’s current, and grow from there. Teaching an agent feels remarkably like onboarding a sharp new hire. The difference is it reads everything you give it, overnight, and never forgets. And you don’t have to teach it everything at once. This is the part worth saying plainly, because the size of an estate can feel paralysing. You are not trying to pour your entire organisation into an agent before it becomes useful. You teach it the parts that matter, and you do it organically — one solution at a time. Start from your toil. Write down the things that actually wake your engineers up, the tasks your team does over and over, the investigation everyone dreads because it takes four hours and always ends the same way. Pick the top one. Coach the agent through that single scenario the way you’d coach a new engineer through their first on-call shift — the context it needs, the sources it should check, the judgement calls that aren’t written down anywhere. Then do the next one. Each scenario you teach is narrow, which means it’s cheap and fast to get right. And each one compounds: the context you gave it for scenario one is already there when you start scenario three. Six weeks in, you’ll notice it knows your system well enough to help with things you never explicitly taught it. Don’t boil the ocean. Boil the thing that’s burning you. Step 3: Create the artifacts — understand the primitives, then build Before you build anything, it helps to understand the three primitives you’re building with — because the difference between them is what gives you consistency. The meta agent is your agent out of the box. It has the LLM’s world knowledge plus all the context you’ve connected — your code, your telemetry, your documents, your memory. It’s versatile: it can investigate, reason, plan, and act. But it’s non-deterministic. Ask it the same question twice and it might take different steps, in a different order, and format its findings differently. That’s fine for exploration. It’s not fine for the 3am incident that needs to run the same way every time. Custom agents give you that consistency. A custom agent is a specialist with its own instructions, its own tools, and its own scope. Think of it as the what — the plan. The Zava learning lab’s learning-ops agent is a good example: it tells the agent exactly how to handle an incident — what to check, in what order, what to post, how to format the report. Every run follows that plan. Custom agents are scoped — they’re only invoked when you specifically ask for them (via /agent in chat, or via a response plan or scheduled task). That scoping is itself a governance lever, which we’ll come back to in Step 5. Skills are the how. They’re reusable procedures that teach the agent how to do a specific thing — query your Kusto cluster, restart a container app, read an IcM incident, run a particular diagnostic sequence. Skills are universal: both the meta agent and any custom agent can use them. A single skill written once is available everywhere. The key insight: the meta agent alone will get you far, but it won’t do the same ten steps next time, or in the same order, or produce the same kind of report. Custom agents and skills give you that repeatability — and repeatability is what you need for automation you trust. Now — how you actually create them. There are exactly two on-ramps, and which one you take depends on whether you already know the answer. Path A — you have a runbook (a known problem). Throw the runbook at the agent and ask it to build the artifacts: the skill, the custom agent, the tool definitions. Review what it produces, refine it, and have it cut a pull request into your repository. A procedure you’d have hand-written over a week arrives in an afternoon. Path B — you don’t (a complex or unknown problem). Work it interactively. Hand the agent the live problem and investigate together. Let it dig, watch it waver, correct its wrong turns, point it at the source it didn’t know about. When you finally crack it — that’s the moment. Ask it to turn what just happened into a custom agent, a skill, a tool. The next time that problem appears, it’s automatic. Path B is the one people don’t expect, and it’s the more valuable of the two. Your best artifacts aren’t written at a desk. They’re precipitated out of real investigations that worked. Every hard incident you solve together becomes an incident you never have to solve again. This isn’t unusual, either — teams everywhere now run skill-creating skills, agent-building skills, and MCP-server-building skills. Using the agent to build more of the agent is simply how this works now. Step 4: Test it — playground first, then non-prod Treat agent artifacts like code, because they are. Start in the playground — a safe space to exercise a skill against realistic inputs without touching anything. Then promote to a non-production system where the agent can act for real against resources that don’t matter. You won’t get everything right before production, and you don’t need to. Get the critical parts right — the core logic, the safety boundaries, the happy path — and then put it on real work. That’s where you find out what it’s actually like. From there, use evals to improve continuously. Every real run produces one, and reading them is how you find out whether the artifact holds up outside the playground. Part Two covers what to do with that signal — including how to wire it back into the artifacts automatically. And because these are production artifacts, they belong in source control from the beginning — with review, diffs, and rollback. Step 5: Govern it — earn the right to automate Remember principle four: governance creates trust. This is where you make it concrete. Before anything touches production, you decide who the agent is, what it’s allowed to do, what rules gate its actions, and what checks run in context. These controls layer on top of each other, and together they’re what lets you say yes to autonomy with confidence. Identity and access Your agent authenticates as a managed identity — system-assigned or user-assigned — and you scope it with normal Azure RBAC at the subscription, resource group, or management group level. Out of the box, Azure SRE Agent offers two access tiers: Reader — read-only access to your resources. This is all your agent needs for investigation, root-cause analysis, and reporting. It’s the right starting point. Privileged — adds resource-type-specific contributor roles (like Container App Contributor) based on what’s detected in your environment. This is what the agent needs for actions: restart, scale, rollback, configuration changes. Most teams start with Reader and add Privileged only on the resource groups where they want the agent to act. If neither tier fits — maybe you want the agent to restart App Services but never touch network rules — create a custom RBAC role with exactly the permissions you need and assign it to the agent’s managed identity. The agent’s identity is its security boundary; treat it the way you’d treat any other service principal. Run mode This is the single biggest lever. In Review mode, the agent proposes actions and waits for a human to approve each one. In Autonomous mode, it acts on its own within the bounds you’ve set. Most teams start every scenario in Review, watch it work for a few weeks, and then selectively move well-understood scenarios to Autonomous. That graduation is the Crawl-to-Run climb in practice. There’s a third thing worth understanding: what happens when the agent doesn’t have the privileges to act. If the agent’s managed identity lacks the RBAC permission for an action, it doesn’t fail silently — it asks. An Administrator can grant temporary elevation via on-behalf-of (OBO), which lets the action execute using the human’s credentials rather than the agent’s identity. This is the human-in-the-loop pattern at its most precise: the agent does the investigation, proposes the action, and a human with the right privileges authorises it in context. The agent never accumulates permissions it doesn’t need permanently, and the audit trail shows exactly who approved what. Tool controls Every tool the agent has access to can be set to one of three states: Allow — the tool executes without asking. Good for safe read operations you’re confident about. Ask — the tool pauses for human approval before running. Good for actions you trust but want to see before they happen. Off — the tool is completely disabled. The agent can’t use it at all. This is the first governance layer — simple, per-tool toggles. Need the agent to query your Kusto cluster but never write to it? Allow the read tool, turn the write tool off. Need it to restart an App Service but never delete one? Allow the restart, turn delete off. This is how you define the agent’s basic operational envelope. Some actions — like restarting a healthy service or scaling up a container app — may not need any gating at all. Others — like modifying a network security group or changing a database configuration — absolutely do. The right setting depends on how much autonomy you want the agent to have and how much you want a human involved. There’s no single right answer; there’s the answer that fits your comfort level today, and it can change tomorrow. Tool access policies Tool controls are per-tool on/off switches. Tool access policies go deeper: they let you write pattern-based rules that match tool names and even command arguments. Examples: - “Deny any command containing delete “ — bash(az * delete *) matches any az ... delete ... command regardless of which tool executes it. - “Allow all monitoring queries without approval” — so your read-only investigation flow runs uninterrupted. - “Ask before any deployment command” — so deploys always pause for a human. Policies apply at three scopes: Scope Who sets it What it can do Global Admin Allow, Ask, or Deny — across the entire agent Custom agent Admin or author Allow only — widen access within global boundaries for a specific custom agent Thread Any user Allow only — temporary override for one conversation The key principle: a global deny cannot be overridden by a lower scope. A custom agent or thread can widen access but never weaken a global deny. This means an admin can set a floor — “nobody, human or agent, can run a delete command” — and know it holds. Hooks Policies match patterns. Hooks evaluate context. This is the layer that handles the cases patterns can’t express. Four hook events: Event When it fires What you’d use it for Start A new thread begins Seed context, validate the trigger, tag the conversation PreToolUse The agent is about to call a tool Inspect the arguments, allow/deny/ask based on what you see PostToolUse A tool just returned Audit the result, flag sensitive output, trigger follow-up Stop The agent is about to finish Validate that the work is complete, reject and keep the loop running if it’s not Hooks can be prompt-based (an LLM judge evaluates the situation) or command-based (a bash or Python script runs deterministically). They sit at the highest priority in the decision chain — a hook allow overrides everything below it, and a hook deny blocks immediately. Here’s where it gets practical. Say the agent is investigating a performance issue and discovers a corrupt database index. It decides to drop and rebuild the index — exactly what a DBA would do. But you don’t want the agent to ever drop a table. How do you allow one and prevent the other? Three layers, working together: Tool access policy: a global deny on any command matching *DROP TABLE* . Pattern-based, unconditional, always enforced. Custom agent scoping: create a database-maintenance custom agent with instructions that explicitly say “you may drop and rebuild indexes; you may never drop tables.” The custom agent only has the database tools it needs — nothing else. The blast radius is contained by design. PreToolUse hook: a script that inspects the actual SQL command. It allows DROP INDEX , denies DROP TABLE , and can require approval for any DDL command above a risk threshold you define. The policy catches the obvious pattern. The custom agent constrains the scope. The hook handles the edge cases that patterns miss. This is the full stack working together. Scoping automations to a custom agent is one of the most powerful governance levers you have. Instead of giving the meta agent broad database access, you create a specialist with its own tools, its own instructions, its own tool access policies, and its own hooks. The meta agent can investigate and recommend. Actual database changes only happen through the custom agent, with guardrails purpose-built for that domain. Who can configure the agent RBAC extends to the agent itself. Four built-in roles govern who can do what: Role What they can do Administrator Full control — approve actions, manage connectors, configure hooks and policies, change run mode, deploy artifacts Author Create custom agents and tools, upload knowledge, author response plans and incident configurations, manage connectors Standard User Chat, run diagnostics, request actions, create scheduled tasks Reader View conversations and configuration — read-only Separation of duties applies here the same way it applies everywhere else: the person who builds a skill shouldn’t necessarily be the person who promotes it to Autonomous. Only Administrators can approve infrastructure actions — Standard Users and Authors cannot. And only Administrators can create hooks and tool access policies, because those controls govern what every other role can do. How it all fits together These controls layer: identity sets the boundary, run mode sets the default posture, tool controls set the envelope, policies set the rules, and hooks handle the judgement calls. They’re not restrictions — they’re what lets you say yes to progressively more autonomy, with evidence that each step is safe. A useful mental model: governance isn’t a gate you pass through once. It’s the dial you turn up gradually, scenario by scenario, as each one proves itself. The agent that’s fully autonomous for certificate renewals and fully gated for database changes isn’t half-governed — it’s precisely governed. Step 6: Promote to production — your agent configuration is code This is the step that turns your dev agent into a repeatable, auditable production system. Your dev agent is your workshop — the place where you experiment, teach, build artifacts, and iterate until things work. Once they do, the configuration you’ve built there becomes your golden state: the skills, custom agents, tool definitions, knowledge base, response plans, scheduled tasks, and memory that together define how this agent operates. All of it can be declared, versioned, and deployed programmatically: Infrastructure as Code — define agents and their configuration in Bicep or Terraform, same as any other Azure resource. Your agent’s entire shape lives in a template. CLI and REST API — create, update, and configure agents with az commands or direct API calls. Useful for CI/CD pipelines that promote artifacts from dev to prod as part of a normal release. Artifact repositories — skills, custom agents, and tool definitions are files in your repo. Push them to your production agent the same way you push code: through a pipeline, with review, with rollback. This means everything your dev agent learned can flow to production through your existing change process. A new skill gets built and tested in dev, reviewed in a PR, merged, and deployed to the production agent by the pipeline — no portal clicking, no manual replication, no drift. It also means consistency across a fleet. If you run multiple agents — per module, per region, per environment — they can all be powered from the same artifact repository. Update the skill once, deploy it everywhere. The agent-per-module pattern from Step 1 works precisely because IaC makes it cheap to keep them consistent. And when something goes wrong, you roll back the same way you roll back anything else: revert the commit, redeploy the template, and the agent is back to its last known-good state. Step 7: Wire it up — an artifact does nothing until something calls it A skill sitting in your repository doesn’t do anything until it’s bound to a trigger — something in your world that fires it without a human deciding to. It’s an easy step to skip, and worth not skipping. There are three you’ll use constantly: Incident response plans. Attach the artifact to an alert class, so that when that alert fires, that skill runs. This is the single highest-value wiring you can do. Scheduled tasks. For work that should happen on a rhythm rather than in response to a signal — the nightly sweep, the weekly review, the monthly audit. HTTP triggers. For everything else in your ecosystem that wants to start agent work: a pipeline stage, a webhook, a work item transitioning to Ready. Here’s why this matters more than it looks. Remember the climb — Crawl, Walk, Run, Fly. Teams often assume they’ll graduate by making the agent smarter. They won’t. A brilliantly capable agent that only ever runs when someone opens a chat window is still at Walk, permanently, because a human is still initiating every piece of work. Capability doesn’t promote you. Triggers do. Wiring is the actual line between Walk and Run. Cross it deliberately. Step 8: Mimic your production process Here’s the step that turns a clever assistant into an operations teammate: the agent should follow the process your humans already follow. Not a parallel workflow. The workflow. An incident arrives → the agent acknowledges it, so everyone can see it’s owned → it investigates, pulling telemetry, correlating recent deploys, checking dependencies → it posts its findings to the incident, where the on-call already lives → it proposes or applies the mitigation → it updates status → it documents the root cause → it resolves. That’s end-to-end incident investigation and remediation, in the same lifecycle, the same ticket, the same channel your team already watches. No new tool to learn. The on-call engineer just notices the work is already done. And this covers more ground than people expect. Most teams think of incidents in three flavours: outages, where something is down; performance issues, where something is slow or degrading; and manual errors — the config change somebody made by hand at the end of a long day, the setting that got flipped in the portal and never made it back into source control. That third category is the one teams under-count and the one agents are unusually good at, because catching it is mostly a matter of comparing what’s running against what was declared — patient, unglamorous work that nobody wants to do at 2am. A worked example. The Zava learning lab agent runs exactly this loop — incident-triggered investigation and remediation across a live estate. Looking at its real runs: a typical end-to-end run takes about 32 tool calls and lands in a 5-to-12-minute band, with a median around 8.6 minutes from signal to finished work. Roughly five minutes to a mitigation, ten to a full resolution. Compare that with what it replaces: a page, someone waking up, ten minutes to orient, a scramble across dashboards, a colleague pulled in for a second opinion. Ninety minutes and two engineers, on a good night. A second example, from the other end of the lifecycle. A large software vendor running a multi-region estate — dozens of subscriptions, tens of thousands of resources — wired their agents into delivery rather than just incidents. A work item moves to Ready, and that’s the trigger. A custom agent picks it up, writes the code, opens the pull request, deploys the change to a test environment, and runs the validation suite against it — synthetic checks and browser-driven tests, the same ones a human would have run. Then it posts the result on the original work item. The engineer’s first involvement is reading an outcome that already has evidence attached. Same five design considerations from Step 1 govern their fleet: one agent per product module, explicit prod and test agents, and one extra agent in-region purely for data residency. These two examples bookend the same idea. One agent closes incidents; the other closes work items. Both were built the same way — context first, artifacts second, triggers third. Beyond incidents — the agent as a proactive partner It’s easy to think of agents as incident responders, because that’s where the value is most visible. But the best teams use them just as heavily when nothing is broken. Understand your system better. Ask the agent to explain your architecture back to you. Ask it what depends on what. Ask it to map the blast radius of a change you haven’t made yet. Ask it to find every resource in your estate that hasn’t been touched in six months, or every configuration that drifts from what’s declared in code. These aren’t investigations — they’re conversations. And the answers come grounded in your actual telemetry and source code, not a wiki page that was last updated in 2023. Get recommendations you didn’t ask for. Set up a scheduled task that reviews your infrastructure weekly and surfaces opportunities: resources that could be right-sized, SKUs that could be downgraded, replicas that could be consolidated, regions where you’re paying for redundancy you’re not using. The same task can check for reliability gaps: services without health probes configured, storage accounts without soft-delete enabled, deployments running without a rollback path. The agent sees all of it because it already has the context — it just needs a reason to look. Run proactive reliability reviews. Ask the agent to evaluate your service against the Azure Well-Architected Framework, or against your own best practices checklist. Ask it to compare your production configuration against your staging configuration and tell you what’s different — and whether the difference is intentional. Ask it to trace a customer-facing flow end to end and identify the single points of failure. Shift from reactive to preventive. This is the compounding value of the platform. Every incident the agent resolves teaches it something about your system. Over time, the agent that started as an incident responder becomes the thing that prevents incidents — because it’s seen enough of your system to spot the preconditions before they become symptoms. The cost analysis that catches the runaway resource before finance does. The capacity check that raises the quota before the 429s start. The configuration audit that catches the drift before it becomes an outage. The agent that only responds to incidents is useful. The agent that also prevents them is transformative. Part Two — Running it well Two loops, not one queue Once agents are working real incidents, the question stops being can it and becomes which ones. Make that a routing decision rather than a judgement call. Run two loops: an agent loop and a human loop. Every incident class is registered to one of them, so where an incident lands is a property of the class, decided in advance — not something someone works out at 3am. Promotion between loops is deliberate. Moving a class into the agent loop is a reviewable change with a written gate, and a written demotion trigger for when it stops earning its place. The safety net belongs to the incident system, not the agent. Define the conditions your process cares about — not acknowledged within x minutes, not mitigated, not handed off — and let the incident system escalate to the human loop when they’re breached. An agent that has stalled can’t be relied on to report that it has stalled; something outside it has to notice. And escalation should carry the work with it, so the human arrives to evidence already gathered rather than a blank page. Cost: know what an outcome costs One of the quietly wonderful things about agentic operations is that you can finally price an outcome. Agents consume metered units, and every unit maps to work. So instead of “what does our on-call cost?” — a question nobody has ever answered honestly — you get: this incident, end to end, cost this much. For the loop above: an entire incident investigated, mitigated, documented and resolved, in minutes, for under $30. Now price the alternative. Two engineers, ninety minutes, out of hours, plus the context-switch tax on whatever they were doing, plus the meeting the next morning to explain what happened. You’re comparing tens of dollars against hundreds — and that’s before you count the ninety minutes of customer impact that didn’t happen because the fix landed in eight minutes instead of an hour and a half. Multiply by your monthly incident volume and it stops being a cost conversation and starts being a capacity one. The question isn’t “can we afford this?” — it’s “what do we do with the engineering time we just got back?” But be careful not to measure the return only in money and minutes, because the larger part of it never shows up on an invoice. It’s the engineer who slept through the night. It’s the on-call rotation people stop quietly dreading, and the weekend that stayed a weekend. It’s the postmortem that never had to be written — and with it, the whole uncomfortable ritual of working out whose change it was — because the problem was caught and fixed while it was still one degraded instance rather than a customer-visible outage. Teams feel that long before finance notices the bill. Morale has always been a reliability metric; it just never had a dashboard. A few practical habits: - Set a consumption budget deliberately, and know who can raise it and how fast before you need them. - Watch cost per resolved outcome, not total spend. Total spend rising while cost-per-outcome falls is exactly what success looks like. - Use the right trigger for the job. Incident response plans and HTTP triggers bring the work to the agent the instant it matters. Scheduled tasks handle the work that belongs on a rhythm — the nightly sweep, the weekly review. Both have a place; the key is matching each scenario to the trigger that fits it. Live Reports — the UI beyond chat Most people first encounter their agent in a chat window, and chat is genuinely good for investigation and conversation. But it’s not the only surface — and for a lot of operational work, it’s not the best one. Live Reports are interactive HTML applications built by the agent and hosted on the platform. They call the same tools the agent uses — Kusto queries, Azure CLI, incident APIs, connector tools — and render the results as charts, tables, grids, and interactive controls. They’re not screenshots of a past conversation. They’re live applications that re-fetch data every time you open them. Here’s the part worth understanding from a cost perspective: the agent spends tokens when it builds the report — the conversation where you describe what you want. After that, opening the report calls the tools directly. No LLM is involved, so there’s no ongoing token consumption. Build it once, open it a hundred times, share it with your team — the investment is in the creation, and it pays off every time someone opens it. Think of Live Reports as the place where your agent’s intelligence becomes a permanent, shareable surface rather than a conversation that scrolls away. Scenarios where Live Reports shine: Morning triage view. What happened overnight? Which incidents are open, which were resolved autonomously, which need human attention? A single page your on-call opens at the start of every shift — always current, no queries to run. Agent fleet health. Across all your agents: which are healthy, which have degraded tool reliability, which haven’t run in a week? Per-tool success rates, outcome counts, cost-per-resolution trending. The monitoring dashboard you’d otherwise build in Grafana, except it’s already wired to the data. Governance and compliance. NSG audit results, CVE exposure by service, resource compliance against your policy baseline. The report that used to take two engineers a day to compile — now it’s a page that’s always current. Cost analysis. Per-agent spend, per-outcome cost, consumption trending with visual charts. The data that makes the cost conversation in Part Two actually work. On-call handover. A shift handoff report: what happened during this rotation, what’s still pending, what to watch. Built once, regenerated for every handover. Stakeholder status pages. Service health for leadership or customers — uptime, incident summary, SLA adherence — without exposing the underlying tools or conversations. Interactive explorers. Not just viewing data but acting on it. A compliance report where you can drill into a finding and ask the agent to open a remediation PR, right from the report surface. The pattern is the same every time: you tell the agent what you want to see, it builds the report, and from that point forward the report is a zero-cost, always-current application that anyone on your team can open. It’s the agent’s intelligence crystallised into a surface that doesn’t need the agent to be running. Monitor the agent You’ll want a few different lenses, because each sees something the others can’t: Layer What it gives you Live reports Your measurement dashboard — autonomy by scenario, throughput, tool reliability — refreshed from your own connectors every time you open it Scheduled tasks The agent reporting on itself: a weekly health narrative, and the loops that keep artifacts current Your own observability platform Independent health and reliability monitoring outside the agent — the layer that still works when the agent doesn’t Foundry Control Plane Auto-discovers your SRE agents across the subscription: status, error rate, run counts, plus start/stop/block lifecycle control, governed by normal Azure RBAC Agent 365 Organisation-wide registry, governance and security posture across every agent platform you run. Agent 365 is generally available; SRE Agent integration into it is on the roadmap One field-tested tip: track tool failure rate per tool, not in aggregate. The overall success rate in large estates typically sits above 98%, which is reassuring — but it can mask a single connector that needs a configuration fix. Watching each tool individually lets you catch those early, and the fix is usually straightforward: a stale token, a permission gap, a connector that needs reconnecting. Knowledge, evals and learning — insist on these Context isn’t a one-time setup. It’s a living asset, and it’s the thing that compounds — but only if your platform is built to let it. This is the section where what you’re running starts to matter a great deal, so it’s worth being direct about what to demand. Insist on an agent that learns without being told to. The common failure mode of agentic tooling is that all the good material stays in the chat thread. Someone works a hard problem with the agent at midnight, finally cracks it, and the reasoning evaporates when the tab closes. What you want instead is derived learning: the agent distils what it just worked out — the query that got there, the dead end worth avoiding, the service that behaves nothing like its documentation — and files it as durable, structured knowledge on its own, without anyone remembering to write it down. Azure SRE Agent does this automatically. Every investigation deposits something. What still needs your attention is the round trip to the original source of truth. Derived learning lives with the agent. Your runbook, your architecture note, your alert definition lives in your repository — and that’s the copy your humans read. Wire the automation that pushes a learning back into the original artifact as a pull request, so the knowledge doesn’t quietly fork into two versions. This is the single most valuable piece of plumbing most teams haven’t built yet. Insist on evals that run forever, not once. Evals get widely misread as a pre-production gate: test the skill, it passes, it ships, done. That’s the smaller half of the value. The bigger half is relentless — continuously evaluating the agent’s real runs in production. Did it stay in scope? Did it reach the right conclusion? Did it stop and ask when it should have? Did that skill quietly start failing at step four last Tuesday? Real traffic finds things no test suite will, and it finds them on your actual estate rather than on a fixture. Then close the loop, so eval results become work rather than a report nobody opens. Azure SRE Agent ships this as a first-class loop: scheduled tasks that watch the eval signal, notice the degradation, and act on it. Self-improvement — where it gets fun Which is where something rather lovely happens: the agent starts improving itself. It notices a runbook is out of date and updates it. It sees a skill failing at the same step and rewrites that step. It spots a recurring investigation and proposes a new custom agent to own it. It watches its own eval scores and opens a pull request against the artifact that slipped. Teams run learning-loop agents alongside their fleets, and watchdog agents that review other agents’ work. Every completed task should make the next task easier. That’s the flywheel — and it only turns when all three pieces are present: knowledge that accumulates by itself, evals that keep scoring real work, and automation wired to act on both. Put them together and the system stops being something you maintain and starts being something that maintains itself. Part Three — The Zero Ops journey: the art of the possible Now the fun part. Here’s what each rung actually feels like, across the scenarios teams really run. Crawl — the agent suggests, you do the work You’ve connected context and you’re asking questions. It’s already useful: “Which of these 40 alerts overnight actually mattered?” — and it tells you, with reasoning. At this rung the governance sweep produces its first report: here are your idle resources, here are the network rules that don’t match policy, here are the CVEs you’re exposed to. Just a list — but it’s a list nobody had time to produce before, and it took four minutes. The certificate scan tells you what expires in the next 90 days. The cost analysis names your top ten spenders and why they moved. The change reviewer reads an incoming change request and tells you, in plain language, what it actually touches and what depends on it — the blast-radius analysis somebody used to do by hand in a change advisory board meeting. You still do all the work. But for the first time, you can see everything. Walk — the agent does the work, one step at a time Now it acts, asking before each step. This is where investigation and root-cause analysis come alive. An alert fires and the agent has already pulled the telemetry, correlated the recent deployment, checked the dependency, and posted a probable cause on the incident — before the on-call has finished reading the title. The question responder starts answering “is the EU region healthy?” in your team channel, with evidence. The governance sweep grows a spine: it doesn’t just list the orphaned resources, it recommends what to do about each. The CVE report becomes a prioritised remediation plan. The change reviewer stops describing the change and starts drafting it — the implementation plan, the validation steps, and the rollback procedure, written before anyone approves anything. You approve every step. It feels slow. It is also where you discover exactly what your agent is good at — and every gap you find becomes tomorrow’s artifact. Run — the agent completes whole tasks; you review the change Triggers are wired now — incidents, webhooks, schedules — and work starts without you. This is the rung where the 3am page stops arriving. The alert-class handler takes a whole class end to end: fires on arrival, investigates, applies the safe mitigation — restart, scale up, roll back the release — documents it, resolves it. You read about it in the morning. This is the rung where the word self-healing finally earns its place. It’s worth being precise about what it means, because it’s a phrase that gets stretched: self-healing is when the agent detects a known failure class, decides on the response, and acts on it within bounds you pre-approved. Not “the agent does whatever it thinks best.” The class is chosen by you. The safe actions are enumerated by you. The agent’s contribution is that it does the work at 3am, correctly, without waking anyone — and tells you exactly what it did. And notice that this is granted per alert class, never per service. It’s completely normal for one fleet to run some classes at near-total autonomy while other classes sit at a deliberate zero, because nobody’s ready yet. That’s not inconsistency. That’s the control working. The capacity agent sees the quota curve heading for a wall and raises it before anything breaks. The certificate agent opens the renewal PR on schedule. The maintenance agent handles the planned work that used to eat somebody’s weekend — the scheduled patching round, the index rebuild, the node pool rotation — running it in the window, verifying it landed, and reporting on it. The change agent executes the approved change in non-production, validates it, and raises the pull request and the change record together. The governance sweep stops recommending and starts acting — opening pull requests against your infrastructure-as-code to close the findings it used to just report. The CVE backlog that only ever grew? It starts going down, because something is working it every single day. And the work-item loop appears: a backlog item goes in, a custom agent writes the code and opens a pull request. You review the diff. Which is exactly when you meet the review wall. Fly — the agent proves the outcome, and improves the system Fly is not “the agent can execute.” It’s two much better things. Fly, part one: the agent can prove the outcome is correct. It builds the fix. It deploys it to a test environment. It runs the validation itself — synthetic checks, browser tests, the full suite. Then it posts the evidence. You stop reviewing the diff and start reviewing the outcome. That’s how the wall comes down. Now the work-item loop closes completely: backlog item → code → deploy → tested → evidence posted. The release-safety agent doesn’t just roll back after an incident, it gates the deploy beforehand — validating in test and blocking the bad one. The governance sweep pushes its own fix to production, having proven in test that it works. And your standard changes — the well-understood, pre-approved, thousand-times-executed ones — get carried out in production end to end, validated, and the change record closed with the evidence attached. The change advisory board stops reviewing procedure and starts reviewing outcomes, which is what it always wanted to be doing. Fly, part two: the agent improves the system. It learns from every incident. It improves knowledge, artifacts, runbooks, skills — and its own custom agents. The alert-quality loop turns inward: it notices which of your alerts are chronic false positives and opens PRs to fix the alert rules themselves. Your monitoring gets better while you sleep. The system gets better without a human editing it. And back to where we started That 3am page? A whole class of them doesn’t reach a person anymore. The fortnight-long cost review? A standing job that finds the waste and opens the PR. The zero-day marathon? The agent maps exposure across every service in minutes, patches in test, proves it works, and hands you evidence. The CVE backlog that only grew? Something works it every day, and it shrinks. That’s Zero Ops. Not zero humans — zero operations for humans. Your people set intent, govern the system, and validate outcomes. Everything below that line takes care of itself. The proof We run Microsoft this way. Every number here is queryable — these aren’t product metrics, they’re trust metrics. Today: - 2,500+ Microsoft engineering teams - 5,400+ agents running in production - Median time from alert to mitigation: 4 minutes To date: - 1.47M incidents processed - 221K mitigated autonomously - 1.25M enriched for the on-call engineer - ~1M developer hours saved* In the last month alone: - 480K incidents handled - 91K mitigated autonomously - 32M agent actions executed - 60K deploy-and-validate runs - 97.9% of agent work ran autonomously That last number is the one worth sitting with. Ninety-eight percent of the work happens with no human in the conversation — and the two percent that does reach a person is the two percent that genuinely needs judgement. In closing It isn’t about building a better agent. It’s about building a system that deserves autonomy. Context makes it intelligent. Governance makes it trustworthy. Metrics make it provable. When those three come together — agents operate, and humans govern. And the best news: you don’t have to build this from the ground up. Azure SRE Agent already carries these learnings — the context, the governance, the evidence, and the metrics — so your team can start today. Pick one scenario. Give it context. Teach it your system. Work a real problem with it, and turn what you learn into something that persists. Then do it again next week. Start your Zero Ops journey: aka.ms/sreagent · Resources and community: aka.ms/sreagent/links *AI-calculated estimate, based on a conservative earlier baseline.What's new in Azure App Service at #MSBuild 2026
At Microsoft Build 2026, Azure App Service introduced a powerful set of updates designed to help organizations accelerate their journey into AI, without increasing complexity or cost. These innovations focus on one clear business outcome: enabling teams to build, deploy, and scale AI-powered applications and agents faster, more securely, and with greater operational efficiency. A key highlight is the new Easy AI experience, which allows existing web apps to become AI-ready with no rearchitecting required. With capabilities like built-in Model Context Protocol (MCP), developers can instantly expose app functionality as agent-ready endpoints, enabling AI agents to interact with business logic securely and seamlessly. This dramatically reduces development time, allowing teams to move from idea to intelligent application in a fraction of the usual effort. Security and compliance are also strengthened with the general availability of Isolated v4 for Azure App Service Environments, delivering improved performance for customers that need single-tenant isolation and strong data residency guarantees. For enterprises operating in regulated industries, this ensures AI applications meet strict governance requirements without sacrificing scalability or speed. For modernization scenarios, Managed Instance on Azure App Service simplifies the migration of legacy applications, including those with OS-level dependencies. Faster restarts, enhanced diagnostics, and AI-assisted migration workflows help organizations modernize existing systems cost-effectively—avoiding expensive rewrites while unlocking AI capabilities. Recent updates include an AI-assisted approach to migrating legacy IIS applications using a multi-agent workflow powered by MCP. Managed Instance is supported on both Premium v4 and Isolated v4, laying the foundation for a modern compute infrastructure across the board. Operational efficiency is further enhanced through platform and CLI improvements designed for the “agent era.” From structured deployment diagnostics to optimized Python pipelines delivering faster deployments, these updates reduce friction and infrastructure overhead, lowering total cost of ownership. Together, these innovations position Azure App Service as a future-ready platform where businesses can rapidly build intelligent, agent-driven applications securely, efficiently, and at scale. 👉 Learn more in the full announcement: Deep dive into Azure App Service Build 2026 updatesDesigning for High Availability: The Operational Reference for Running a Geo-Replicated ACR
By Johnson Shi, Zoey (Zhuyu) Li, Huangli Wu Introduction Three of the most common questions we hear from enterprise teams running geo-replicated Azure Container Registries (ACR) are: "How do I control which region serves my traffic?" — When my AKS clusters are spread across regions, can I pin each one to its co-located replica, or am I stuck with however the global endpoint routes? "What happens during a regional incident — is failover automatic or do I have to act?" — If the registry in one region degrades, does the global endpoint reroute on its own, or do I need to manually disable the affected replica? "What happens after the region recovers — does traffic return on its own?" — Is there a cooldown, a quarantine, or any manual step before failback? We answer those head-on, then go deeper on the operational details that come up when you actually run a geo-replicated registry: authentication across endpoint switches, throttling under load concentration, eventual-consistency failure modes, home region outage scope, webhooks, and private endpoint interaction. We draw on the official geo-replication docs, the global endpoint health-aware failover blog, the regional endpoints engineering design implementation, the regional endpoints public preview and private preview announcements, and the ACR reference for various registry endpoints, . This post also draws notes from the ACR product team on roadmap items that aren't yet documented elsewhere. Key Takeaways Health-aware failover is automatic. When the registry in a region degrades, the global endpoint reroutes away from it on the order of minutes, evaluated per-registry. No customer action required. Failback is automatic too. Once health-aware failover marks a region healthy again, the global endpoint resumes routing to it. There is no cooldown period. Health-aware failover applies only to global endpoint operations. It does not apply to regional endpoints (you're talking to one replica, period) or to dedicated data endpoints (the redirect is per-region). Health-aware failover is not triggered by throttling. It responds to regional ACR service health and Azure infrastructure health, not HTTP 429 responses. Use regional endpoints to manage per-replica throttling. Regional endpoints (Step 2a) give you explicit per-region URLs for workloads that need affinity, capacity planning, push/pull consistency, troubleshooting, or client-side failover. Use myregistry.<region>.geo.azurecr.io . Regional endpoints are available on Premium SKU registries. For workloads that don't need pinning, do nothing (Step 2b). The global endpoint plus health-aware failover handles routing automatically. Re-authenticate when switching endpoints. Each global or regional endpoint is its own authenticated surface; re-auth via az acr login , SDK auth, or the Kubernetes ACR credential provider on endpoint change. Don't run a long-lived DNS cache for the global endpoint. ACR purges DNS server-side on disable and during failover; a long-lived client cache works against that. For production workloads, enable dedicated data endpoints for security and DNS predictability on layer downloads. ACR is working on bounded staleness consistency for cross-replica eventual-consistency failure modes; see the FAQ. Background What is ACR geo-replication? Geo-replication is a Premium SKU feature that turns a single ACR registry into a multi-region, multi-write service. Every geo-replica in every region is writable — you can push, pull, and delete from any of them — and content syncs asynchronously between replicas under an eventual consistency model. Per-push replication time scales with the size and number of images being pushed. Similarly, when creating a new geo-replica, the time to populate the new geo-replica scales with the total size of the registry. A geo-replicated registry exposes a global endpoint at myregistry.azurecr.io . Behind that endpoint, ACR uses an internal traffic manager to direct each request to the replica with the best network performance profile for the caller — usually the closest replica, but not always. When clients are equidistant from multiple replicas, or when the closest replica is experiencing Azure infrastructure degradation, requests may be routed elsewhere. A geo-replicated registry also exposes a regional endpoint at myregistry.<region>.geo.azurecr.io , which allows clients to pin API requests to a specific geo-replica in lieu of global endpoints, which has Azure-managed routing among geo-replicas. Zone redundancy is always enabled for geo-replicas in regions where Azure has multiple availability zones — in those regions, ACR automatically spreads replica data across multiple availability zones within each region to protect against zonal outages. Endpoints and data endpoints: what goes where A common point of confusion: when you push or pull, not every request goes to the same place. The registry endpoints (global endpoint and regional endpoints), as well as the data endpoint, do different jobs. Your choice of data endpoint configuration has real consequences for security and resilience. Two kinds of traffic flow during a typical pull: Registry API traffic — authentication, manifest reads/writes, tag resolution, referrers, repository operations, blob location lookups, listing, metadata. This is everything except the actual layer (blob) bytes. All these API requests go to the global endpoint ( myregistry.azurecr.io ) or, if you've pinned your clients to call these APIs to a specific geo-replica, a geo-replica's regional endpoint ( myregistry.<region>.geo.azurecr.io ). Behind the scenes, the global endpoint internally proxies these requests to a specific geo-replica. Layer (blob) downloads — when the client asks for a blob, the registry doesn't serve the bytes itself. It returns an HTTP 307 redirect to a regional data endpoint (separate endpoint from the global endpoint or regional endpoints), and the client follows the redirect to download the layer from that region. Where that 307 sends you depends on whether you've enabled the registry's dedicated data endpoints feature: Configuration Layer downloads redirect to Default (no dedicated data endpoints) *.blob.core.windows.net (the underlying Azure storage account) Dedicated data endpoints enabled myregistry.<region>.data.azurecr.io for the region you were routed to Private endpoints enabled myregistry.<region>.data.azurecr.io for the region you were routed to Regional by design. Dedicated data endpoints always land you on a specific geo-replica's data endpoint — there is no "global data endpoint." With the global endpoint as your registry endpoint, the 307 redirect picks the data endpoint for whichever region the global endpoint chose to serve you. With a regional endpoint pinned to a specific region, the 307 always redirects you to that same region's data endpoint — never cross-region. Why dedicated data endpoints matter. Dedicated data endpoints are a Premium SKU feature that exists primarily to address security and firewall scoping. By default, layer downloads redirect to *.blob.core.windows.net — a wildcard storage FQDN. Firewall rules to allow that wildcard either let all Azure storage accounts through or none of them, which raises data exfiltration concerns and isn't tightly scoped to your registry. Dedicated data endpoints replace the wildcard with a fully qualified domain in your registry's own domain — myregistry.<region>.data.azurecr.io — so firewall rules can be scoped tightly to your specific registry, in your specific regions. That same design choice can also make layer downloads more predictable during routing changes. With dedicated data endpoints, the data endpoint FQDN is known ahead of time and lives in the registry's domain — one predictable hostname per region, configured once. Without them, the layer download has to resolve a wildcard storage FQDN that points to whichever storage account the registry happens to have provisioned, which is a separate DNS resolution path with its own routing behavior and its own caching profile. Dedicated data endpoints simplify the DNS picture by aligning the data path with the registry path and keeping the entire pull experience inside one set of predictable, scoped FQDNs. For any geo-replicated registry where security and high availability matter, enable dedicated data endpoints. Note: Health-aware failover applies only to operations against the global endpoint, not to regional endpoints or dedicated data endpoints. Take note that health-aware failover only kicks in and directs traffic away from a geo-replica when an Azure region is experiencing significant infrastructure degradation. At this stage, it does not kick in to redirect traffic to another geo-replica if a client's data plane API requests are throttled. See the relevant section below for the full scope when health-aware auto failover kicks in or not. The three traffic control tools ACR geo-replication gives you three complementary tools for controlling where traffic lands. Each one solves a different class of problem, and customers most often run into trouble when they reach for the wrong one. We name them up front and use these names throughout the post: Tool Who controls it What it does Use cases Health-aware failover Platform (automatic) Reroutes the global endpoint away from a region whose registry can't reliably serve requests Regional incidents, automatic recovery Replica enable/disable for global routing Customer (manual) Excludes a specific replica from global endpoint routing without deleting it; data continues syncing DR rehearsals, planned maintenance, quarantining a replica without losing it Regional endpoints Customer (per request) Dedicated per-region URLs ( myregistry.<region>.geo.azurecr.io ) that bypass the internal traffic manager entirely Pinning AKS clusters to co-located replicas, push/pull consistency, capacity planning, troubleshooting, client-side failover Health-aware failover and replica enable/disable both act on the global endpoint. Regional endpoints are a separate URL surface that coexists with the global endpoint — enabling them does not disable the global endpoint myregistry.azurecr.io . You can use both simultaneously and choose per workload. The behavior in question When the registry in one region experiences a real degradation, there are three possible answers to "what happens?": (A) Nothing automatic. The customer must manually disable the affected region's endpoint to stop traffic from being routed there. (B) The system detects the regional front-door failure and reroutes within seconds. (C) A per-registry health evaluation detects the degradation and reroutes the global endpoint within minutes, with no customer action. After the region recovers, routing resumes automatically. The answer today is (C). Before health-aware failover, customers were stuck closer to (A) — the system could see whether the regional reverse proxy responded, but not whether the registry could actually serve real pull and push traffic end to end. Health-aware failover closes that gap. We walk through all three tools in the next section, in order: setting up geo-replication, using regional endpoints to pin specific workloads, keeping the global endpoint for everything else, the manual replica disable mechanism, re-enabling participation in global routing, and what to expect when health-aware failover triggers. Walkthrough The following steps assume an existing Premium SKU registry and the Azure CLI logged in. We use myregistry as the registry name, myrg as the resource group, and eastus as the home region. Substitute <your-registry> , <your-rg> , and <your-region> for your environment. Prerequisites A Premium SKU ACR registry (geo-replication requires Premium) Azure CLI ( az ) installed and logged in For regional endpoints (Step 2a): Azure CLI 2.86.0 or later. All regional endpoints commands ( --regional-endpoints , az acr show-endpoints , az acr login --endpoint ) are available natively in Azure CLI 2.86.0+. If you previously installed the acrregionalendpoint private preview CLI extension, uninstall it with az extension remove --name acrregionalendpoint to prevent conflicts with the built-in CLI commands. Step 1: Add a West US replica to a registry that lives in East US Geo-replication requires the Premium SKU. The create call below fails on Basic or Standard. # Confirm the registry is Premium az acr show --name myregistry --resource-group myrg \ --query sku.name --output tsv # Premium # Create a West US geo-replica az acr replication create --registry myregistry --location westus # Confirm both replicas are present az acr replication list --registry myregistry --output table NAME LOCATION PROVISIONING STATE STATUS REGION ENDPOINT ENABLED ------ ---------- -------------------- -------- ----------------------- eastus eastus Succeeded online True westus westus Succeeded online True Pushes and pulls continue working through the existing replica throughout initial sync. Because the registry is multi-region, multi-write, the existing replica keeps serving traffic while the new replica catches up in the background. Initial replica seeding time is a function of registry size — the total number and cumulative size of images already in the registry that need to be replicated to the new replica — not the size of any single image. Step 2a: Pin workloads to specific regions using regional endpoints Use regional endpoints when a workload needs explicit per-region control. The five common cases: Regional affinity — an AKS cluster in East US should pull from the East US replica, every time, without ever hopping to a more distant replica because of a network performance fluctuation. Predictable routing — workloads that need to know exactly which replica will serve them, for benchmarking, capacity planning, or in-region traffic SLAs. Push/pull consistency — pinning both ends of a publish-then-deploy flow to the same replica eliminates eventual-consistency races. Troubleshooting — reproducing an issue on a specific replica requires sending traffic to that specific replica. Client-side failover — customers with their own health checks and business rules want to implement failover on their own terms, on signals only they can see. Enable regional endpoints on the registry: az acr update -n myregistry -g myrg --regional-endpoints enabled When enabled, ACR automatically creates per-region login server URLs for every existing geo-replica. No per-region configuration is needed. Note: Regional endpoints can be enabled on any Premium SKU registry, even without geo-replication. A registry without geo-replication has a single geo-replica in the home region, which gets one regional endpoint URL. However, the feature is most useful when your registry has at least two geo-replicas, where you can pin different workloads to different replicas for routing control and capacity distribution. Push to a specific region using its regional endpoint: # Log in to the West US regional endpoint az acr login --name myregistry --endpoint westus # Tag and push using the regional endpoint URL docker tag myapp:v1 myregistry.westus.geo.azurecr.io/myapp:v1 docker push myregistry.westus.geo.azurecr.io/myapp:v1 Pin AKS deployments to their co-located replica by using regional endpoint URLs in the deployment manifest. The example below shows two clusters in different regions; each cluster references the regional endpoint for its own region's replica (assuming replicas exist in both eastus and westeurope ): # East US-based AKS cluster pulls from the East US replica apiVersion: apps/v1 kind: Deployment metadata: name: myapp-eastus spec: template: spec: containers: - name: myapp image: myregistry.eastus.geo.azurecr.io/myapp:v1 --- # West Europe-based AKS cluster pulls from the West Europe replica apiVersion: apps/v1 kind: Deployment metadata: name: myapp-westeurope spec: template: spec: containers: - name: myapp image: myregistry.westeurope.geo.azurecr.io/myapp:v1 This eliminates cross-region pulls when global routing would otherwise prefer a different replica for a given client, and it gives you a per-region traffic profile you can plan capacity against. Regional endpoint operational tips View all endpoints. Use az acr show-endpoints to see all endpoint URLs for your registry — global, regional (if enabled), and dedicated data endpoints (if enabled): az acr show-endpoints --name myregistry --resource-group myrg Import from a specific geo-replica. When importing images between registries, you can use a regional endpoint to import from a specific geo-replica of the source registry. This is useful when you want predictable network paths or need to import from a replica in a specific region: az acr import \ --name mydownstreamregistry \ --source myupstreamregistry.westeurope.geo.azurecr.io/myapp:v1 \ --image myapp:v1 Firewall rules for regional endpoints. If you use firewall rules, allow access to the following endpoints for each geo-replica that clients connect to: Endpoint Purpose myregistry.<region>.geo.azurecr.io Regional endpoint for registry operations myregistry.azurecr.io Global endpoint (if also used) myregistry.<region>.data.azurecr.io Layer downloads (if using private endpoints or dedicated data endpoints) *.blob.core.windows.net Layer downloads (if not using private endpoints or dedicated data endpoints) For the full list of endpoint types and FQDN patterns, see the ACR reference for various registry endpoints. DNS-based routing without changing manifests. If you don't want to maintain different deployment manifests per region, you can keep all manifests pointing to the global endpoint ( myregistry.azurecr.io ) and use software-defined networking or a regional traffic manager to resolve the global endpoint to the appropriate regional endpoint based on the originating region's traffic. This achieves the same co-location goals as regional endpoints — predictable routing and reduced latency — without embedding region-specific URLs in your deployment manifests. Step 2b: Keep using the global endpoint for everything else For workloads that don't need explicit pinning, do nothing. The global endpoint at myregistry.azurecr.io continues to work exactly as before, and the global endpoint plus health-aware failover gives you intelligent routing across replicas without configuration. ACR picks the best replica for each client based on network performance and reroutes during regional incidents. Regional endpoints coexist with the global endpoint — enabling them does not disable myregistry.azurecr.io . You can use both simultaneously and choose per workload, mixing pinned workloads (Step 2a) with workloads that ride the global endpoint (Step 2b) in the same registry. Step 3: Take a replica out of global endpoint routing Use this when you need to keep a replica alive but stop it from serving global-endpoint traffic — for DR rehearsals, planned maintenance, or troubleshooting an isolated replica. # Exclude the West US replica from global endpoint routing az acr replication update --registry myregistry --name westus \ --global-endpoint-routing false Confirm the change: az acr replication list --registry myregistry --output table NAME LOCATION PROVISIONING STATE STATUS REGION ENDPOINT ENABLED ------ ---------- -------------------- -------- ----------------------- eastus eastus Succeeded online True westus westus Succeeded online False Requests to myregistry.azurecr.io no longer route to West US. The replica still receives replicated content — and continues to replicate its own content out to other replicas — and storage quota and per-replica costs continue to accrue. If regional endpoints are enabled, the West US regional endpoint URL also continues to work; --global-endpoint-routing controls only the replica's participation in global endpoint routing. A note on naming. The CLI flag --global-endpoint-routing (on az acr replication update ) and the regional endpoints feature (enabled via az acr update --regional-endpoints enabled ) are two different things despite the similar names. --global-endpoint-routing controls whether a replica participates in global endpoint routing. The regional endpoints feature creates per-region URLs ( myregistry.<region>.geo.azurecr.io ) that bypass the global endpoint entirely. They are independent controls. In Azure CLI 2.86.0 and later, the old --region-endpoint-enabled flag has been renamed to --global-endpoint-routing . The old flag name is deprecated and will be removed in Azure CLI 2.87.0 (June 2026). If you have existing scripts or automation that use --region-endpoint-enabled , update them to use --global-endpoint-routing . CLI flags quick reference: Flag Scope Purpose --regional-endpoints Registry-level ( az acr create or az acr update ) Enables dedicated regional endpoint URLs ( myregistry.<region>.geo.azurecr.io ) for all geo-replicas. --global-endpoint-routing Per-geo-replica ( az acr replication create or az acr replication update ) Controls whether the global endpoint routes traffic to a specific geo-replica. Set to false to temporarily exclude a geo-replica from global routing. --data-endpoint-enabled Registry-level ( az acr create or az acr update ) Enables dedicated data endpoints ( myregistry.<region>.data.azurecr.io ) for layer blob downloads. Auto-enabled when at least one private endpoint is configured. This bidirectional sync during disable is intentional. When you re-enable the replica, every image pushed to the registry while the replica was disabled — from any region — is already present, so the replica can serve traffic immediately with no catch-up window. If we stopped syncing on disable, re-enabling would leave the replica with stale data and force a long catch-up before it could safely serve pulls. Step 4: Re-enable the replica to participate in global endpoint routing Re-enable the replica: az acr replication update --registry myregistry --name westus \ --global-endpoint-routing true NAME LOCATION PROVISIONING STATE STATUS REGION ENDPOINT ENABLED ------ ---------- -------------------- -------- ----------------------- eastus eastus Succeeded online True westus westus Succeeded online True There is no cooldown. The global endpoint resumes routing requests to the West US replica as soon as the change takes effect on ACR's side. Because data continued syncing while the replica was disabled (Step 3), the replica is immediately ready to serve pulls — no catch-up window. Note on DNS during disable/enable. When you take a replica out of global routing, ACR purges its own DNS records for that replica from the global endpoint on a fast path — there is no waiting on a published TTL on ACR's side. If clients run their own DNS cache for the global endpoint, however, those clients will keep resolving to the disabled replica until the client cache expires. We can't control client-side caches. The recommendation: do not run a long-lived DNS cache for the global endpoint. A short-lived DNS pin for the duration of a single push (covered in the DNS and Client-Side Considerations section) is fine and even helpful — but a long-lived DNS cache will make --global-endpoint-routing false look broken from the client's perspective. Step 5: What to expect when health-aware failover triggers Health-aware failover is automatic. ACR evaluates registry health on a per-registry basis, and when a registry in a region can't reliably serve requests, the global endpoint reroutes that registry's traffic to a healthy replica. There is no customer-invocable trigger — that's the point. End-to-end timing is on the order of minutes — fast enough to catch real regional degradation, slow enough to ride out transient errors that resolve on their own. DNS TTL may add additional propagation delay before all clients switch to the new region. Scope of health-aware failover. Health-aware failover applies only to operations against the global endpoint — the registry API calls (auth, get manifest, get tag, get referrers, get blob location). It evaluates health when those API calls come in; it does not trigger mid-operation. Two important consequences: Regional endpoints are not in scope. When you talk to a regional endpoint like myregistry.westus.geo.azurecr.io , you're talking to that one replica. There is no automatic reroute. If you've pinned a workload to a regional endpoint and that region degrades, you implement client-side failover by switching the workload to a different regional endpoint. Dedicated data endpoints are not in scope. Once a registry endpoint has redirected you to a dedicated data endpoint, you stay on that region's data endpoint for the duration of the layer download. There is no automatic reroute of an in-flight blob download. The region targeted by the redirect is decided up front by whichever registry endpoint served the blob-location call: the global endpoint chooses based on its per-registry health evaluation, and a regional endpoint always targets its own region. The signals you can use to confirm a failover is in progress: # Check replication status az acr replication list --registry myregistry --output table You can also check Resource Health for the registry in the Azure portal — navigate to your registry and select Resource health under the Help section to see platform-side degradation signals. You'll typically see: Increased pull latency as traffic shifts to a more distant replica Resource Health flagging known issues in the affected region Replication status indicating which replicas are online After the region recovers, the per-registry health evaluation marks it healthy again and the global endpoint resumes routing — automatic, no cooldown, no customer action. Note that health is evaluated per registry, not per region: if a degradation affects only a subset of registries in a region, only those registries are rerouted, and other registries in the same region continue to be served locally with no unnecessary latency penalty. Not triggered by throttling. Health-aware failover is DNS-based and responds to regional ACR service health and Azure infrastructure health. It does not reroute traffic based on HTTP 429 (throttling) responses. If a geo-replica is throttling your requests but the region's infrastructure is healthy, the global endpoint continues routing you to that geo-replica. To manage throttling, use regional endpoints to spread workloads across multiple geo-replicas for better capacity distribution. Note on long-running pushes during a failover. A multi-layer push that spans a failover boundary can land layers and the manifest on different replicas — exactly the failure mode that DNS bouncing produces during a single push. ACR is actively tightening health-aware failover behavior to minimize cross-replica scatter during these scenarios, and the recommendation today remains: pin pushes to a single replica via a regional endpoint when push/pull consistency matters. Common Questions Q1. Performance impact during initial replica creation on a live registry Because ACR is multi-region, multi-write, the existing replica continues serving pull and push traffic throughout the period when a new replica is being seeded. Replication is asynchronous and content propagates in the background; the time to populate a new geo-replica scales with the size of the registry — the cumulative number and total size of images already in the registry — not with any single image. The docs do not publish a quantified degradation percentage or a throttling window for this period, and they do not promise zero performance impact — the safe operating assumption for a live production registry is that existing replicas continue serving traffic normally, with the new replica catching up in the background. Q2. Restricted/updating state during initial sync There is no "restricted" state for the registry during normal replica creation. Writes, control-plane operations, and pushes/pulls against existing replicas continue normally. The only time configuration changes are unavailable is during a home region outage — see the relevant FAQ item later on for the full data-plane-versus-control-plane breakdown. Q3. Cooldown periods and non-straightforward failback scenarios There is no cooldown before failback, manual or automatic. Re-enabling a replica's participation in global endpoint routing takes effect immediately on ACR's side. Health-aware failover returns traffic to a region as soon as its per-registry health evaluation passes again. The failback case that is not seamless: if a recently pushed image has not yet replicated to the failover region, a pull from that region may not find the image until replication catches up. This is a function of eventual consistency, not failback timing — and it's part of a broader class of issues we cover in Q4. Q4. Common pull and push failure modes during the eventual-consistency window DNS bouncing during a single push is one well-known problem, but it isn't the only one. The eventual-consistency window between geo-replicas surfaces in several recurring failure modes worth knowing about: Push-then-immediate-pull-cross-region. Pushing myapp:v1 to one region and immediately pulling it from a different region can fail with manifest unknown until replication catches up. This shows up most painfully in CI/CD pipelines where one CI runner pushes an image and thousands of pods across other regions all try to pull from their local geo-replicas at the same time. Today, customers work around this with indeterminate sleeps before scheduling expensive compute, or with retry logic, or by waiting on a replication-complete signal — none of which is a clean planning story. Tag overwrite races. Pushing myapp:v1 , then re-pushing myapp:v1 shortly after with a fix (same tag, different digest), can leave different replicas resolving the same tag to different digests during the eventual-consistency window. Delete propagation. Deleting a tag or repository in one region takes some time to propagate to other replicas. Pulls from regions where the delete hasn't yet propagated can return the supposedly-deleted content. Mid-push failover scatter. A multi-layer push that spans a health-aware failover boundary or a DNS bouncing event can land layers on one replica and the manifest on another, surfacing as manifest validation errors or blob unknown on subsequent pulls. What ACR is doing about this. We're working on bounded staleness consistency for pushed images across all geo-replicas worldwide, which addresses these four failure modes directly. This will be covered in an upcoming blog post. If you're hitting eventual-consistency brittleness today and want to talk through your scenario, reach out to us on the Azure Container Registry GitHub repository — we want the customer signal to land in the design. Mitigations available today: Pin pushes to a single replica via a regional endpoint. Every sub-request in the push — login, blob uploads, manifest upload — goes to the same replica, eliminating the DNS bouncing and mid-push scatter classes entirely. Use a short-lived client-side DNS cache like dnsmasq scoped to the duration of a single push, only when you're not using regional endpoints. Do not run a long-lived DNS cache for the global endpoint — it interferes with --global-endpoint-routing false and with health-aware failover routing. Build retry logic into pulls that immediately follow a cross-region push. Either retry with backoff or check replication status with ACR webhooks before pulling. ACR can detect and notify you when an image or tag is available for pull in a geo-replica (say geo-replica B), after it has been pushed to another geo-replica (geo-replica A) and background replication has succeeded to geo-replica B. Design publish steps to be idempotent so retries triggered by mid-push failover are safe. Q5. Auth behavior across endpoint switches For safety, treat each global endpoint and each regional endpoint as its own authenticated surface. All registry APIs except the actual blob downloads (auth, manifests, tag resolution, referrers) flow through whichever endpoint you've chosen. If you switch from the global endpoint to a regional endpoint, or from one regional endpoint to another, re-authenticate. That means az acr login , fresh SDK auth, or — for AKS — letting the Kubernetes ACR credential provider handle re-auth, which it does automatically when the endpoint changes. Q6. Throttling under failover and pinning Throttling limits on registry API operations are per-replica, not per-registry. This has two operational implications: During health-aware failover, traffic that was spread across replicas can shift heavily onto whichever replicas remain in the global endpoint's routing pool. Capacity plan to spread traffic across two or three healthy replicas during a failover scenario rather than concentrating onto one — the global endpoint's routing already does this for you when multiple healthy replicas exist, but registries with only two regions configured can hit per-replica limits more easily during a failover. To mitigate, use regional endpoints to spread workloads across multiple geo-replicas and plan per-replica capacity. When pinning via regional endpoints (Step 2a), you concentrate traffic on whichever replica you've pinned to. If you've pinned all your AKS clusters to a single regional endpoint, you may hit that replica's per-region throttling limits at peak. Mitigations: pin different workloads to different regional endpoints across multiple regions for better topology mapping and capacity distribution, or use the global endpoint (Step 2b) for workloads where you don't need explicit pinning so ACR's routing can spread load. We're also working on improving the throttling metrics surfaced during health-aware failover events. Note: Health-aware failover does not reroute traffic based on HTTP 429 (throttling). If you're experiencing throttling but the region's infrastructure is healthy, the global endpoint continues routing you there. Use regional endpoints to explicitly spread load across replicas for capacity planning. Q7. Home region outage scope Geo-replication provides high availability for the data plane. During a home region outage, the control plane is unavailable, which means you can't create or delete replicas, modify network rules, or change replication settings until the home region recovers. ACR Tasks are also bound to the home region and don't run while it's unavailable. The data plane keeps working: Global endpoint continues routing pulls and pushes to healthy replicas. Regional endpoints continue working — you talk directly to specific replicas, and your client-side logic decides which region to use. Authentication, manifests, blob downloads, webhooks continue functioning through any healthy replica. The home region of a registry is fixed at creation and cannot be changed afterward. Microsoft's registry relocation guidance describes a redeployment procedure — creating a new registry in a different region — not an in-place change to an existing registry's home region. Note: If your registry uses a customer-managed key, review the key vault failover and redundancy guidance for maximum resilience. Key vault availability directly affects the registry's ability to encrypt and decrypt data. Q8. Webhooks during failover Webhooks fire from the replica that received the push. Because ACR also replicates content to other geo-replicas, webhooks fire from each geo-replica as the image syncs to it — so a single push results in webhook events from the receiving replica plus an event from each replica as replication completes. During a failover where pushes are routed to a different region, webhooks from those pushes fire from the new region; once the original region recovers and replication catches up, webhook events fire from there too. Webhook consumers should be designed to handle multiple events per pushed image and deduplicate as needed. Q9. Private endpoints with regional endpoints and dedicated data endpoints When a private endpoint is created against a registry, the private endpoint covers all of the registry's endpoint surfaces — the global endpoint, every regional endpoint (if regional endpoints are enabled), and every regional dedicated data endpoint. A single private endpoint in one VNet can reach the global endpoint (which routes you to a suitable replica), any regional endpoint in the same or a different region, and any region's dedicated data endpoint for blob downloads. The trade-off is private IP allocation: each endpoint surface consumes IPs in the VNet. With many replicas plus regional endpoints plus dedicated data endpoints all enabled, private endpoint creation can fail if the VNet runs out of available private IPs. IP address consumption per feature: Configuration IPs consumed per VNet Initial private endpoint (global endpoint + home region dedicated data endpoint) 2 Each geo-replication region added +1 (regional dedicated data endpoint) Regional endpoints enabled +1 per geo-replica Example: A registry with 3 geo-replicas and regional endpoints enabled consumes 7 private IPs per VNet: 1 (global) + 3 (data) + 3 (regional). Without regional endpoints, the same registry requires 4 private IPs: 1 (global) + 3 (data). Subnet sizing: Use at minimum a /27 (32 addresses) subnet for PE subnets on geo-replicated registries, and /24 where possible. To check how many private IPs are already consumed on a subnet: az network vnet subnet show \ --name <subnet-name> \ --vnet-name <vnet-name> \ --resource-group <resource-group> \ --query "{addressPrefix:addressPrefix, usedIPs:length(ipConfigurations || \`[]\`)}" \ --output table See the ACR private endpoints documentation for the full IP-allocation math and sizing guidance. Q10. Geo-replica creation stuck for private endpoint-enabled registries When creating a geo-replica for a registry that has private endpoints configured, the replica provisioning can get stuck in a Creating state if the identity performing the operation doesn't have sufficient permissions to create private endpoint networking resources. Solution: Manually delete the geo-replica that got stuck in the provisioning state. Ensure the identity has the permission Microsoft.Network/privateEndpoints/privateLinkServiceProxies/write before creating the geo-replica again. Also verify that every PE subnet connected to the registry has free IP capacity — if any PE subnet across any connected VNet does not have enough free IPs, the replication provisioning fails and rolls back. The replica appears briefly in a Creating state and then is removed. The resulting error does not identify which subnet or VNet is exhausted. Q11. Metrics, logs, and alerts for the three phases We map each phase to the signals available in the Monitoring Guidance section below. The headline: Resource Health (in the Azure portal) and az acr replication list give you the platform-side signals; Azure Monitor platform metrics are collected automatically, and resource logs require Diagnostic Settings to be enabled on the customer side. Behavior summary Scenario Automatic? Customer Action Required Notes Registry in a region degrades Yes None Health-aware failover; per-registry; minutes-scale; global endpoint operations only Region recovers after a degradation event Yes None No cooldown Pin AKS clusters to co-located replicas No Use regional endpoint URLs in deployment manifests (Step 2a) Coexists with global endpoint No pinning needed for most workloads Yes None — keep using myregistry.azurecr.io (Step 2b) Global endpoint plus health-aware failover Push/pull from the same replica (consistency) No Use a regional endpoint for both push and pull Eliminates DNS bouncing and mid-push scatter Capacity planning per region No Spread workloads across multiple regional endpoints Per-replica throttling; avoid concentrating on one replica DR rehearsal: take a replica out of global routing No az acr replication update --global-endpoint-routing false Data continues syncing both directions; costs continue accruing Re-enable replica participation in global routing No az acr replication update --global-endpoint-routing true No cooldown; replica is immediately ready Switch a workload between endpoints No Re-auth ( az acr login , SDK auth, or Kubernetes ACR credential provider) Each endpoint is its own authenticated surface Initial replica seeding on a live registry N/A None Existing replica continues serving traffic; seeding time scales with registry size Long-running push during a failover No Retry; design publishes to be idempotent Pin via regional endpoint to avoid mid-push scatter; ACR is tightening this behavior Pull of a recently pushed image from a different region No Wait for replication, retry with backoff, or check replication status Eventual consistency; bounded staleness consistency in development Home region outage Data plane: yes; control plane: no Use global or regional endpoints for data plane operations Control plane (replica config, network rules) requires home region DNS and Client-Side Considerations DNS bouncing during a single push is the most common geo-replication push problem in customer threads, and it warrants a section of its own. The failure mode. A docker push is a sequence of HTTP requests: blob uploads for each layer, then a manifest upload that references those layers by digest. If the Linux DNS resolver on the client doesn't cache myregistry.azurecr.io consistently for the duration of the push, individual sub-requests can resolve to different replicas. Because replication is eventually consistent, the manifest can land on a replica that doesn't yet have the layers it references, and the manifest validation fails. The two mitigations: Regional endpoints pin the push to a single replica end-to-end. Every sub-request — login, blob uploads, manifest upload — goes to the same replica. This is the cleanest fix and the one we recommend for any pipeline where push/pull consistency matters. A short-lived client-side DNS cache like dnsmasq scoped to the duration of a single push. For Linux VMs in Azure, follow the DNS name resolution options guidance. The pin should last the push and no longer. For other clients performing pushes, you can customize your stack's DNS resolver to have a similar short-lived DNS cache to pin the global endpoint's resolved DNS for only the duration of an image push operation. A note on long-lived DNS caching for the global endpoint. Don't run a long-lived DNS cache for myregistry.azurecr.io . ACR purges its own DNS records on the server side when a replica is taken out of global routing (Step 3) and during health-aware failover; a long-lived client-side cache will keep clients pointed at the old region after our purge, which makes both the manual disable mechanism and health-aware failover look broken from the client's perspective. Retry behavior: In-flight pushes during a failover may fail. Design publish steps to be idempotent so retries are safe. Pipelines that push in one region and immediately pull from a different region should retry with backoff or check replication status — eventual consistency means the pull may race ahead of replication. ACR is working on bounded staleness consistency that addresses this directly by enabling proxying (on ACR infrastructure) an image pull request from one geo-replica (if it does not have the image) to another geo-replica that has the image; see the relevant FAQ item. Note: Specific retry counts, back-off intervals, and push timeout values are application-layer decisions. The platform behavior is documented; the retry policy belongs to your client. Monitoring Guidance We map the three phases to the signals available from each source. Where a signal requires customer-side configuration, we flag it. Phase A: Initial replication (after creating a new replica) az acr replication list and az acr replication show — confirm the new replica reaches provisioningState: Succeeded and status: online , and view per-replica status. Azure Monitor platform metrics — push count, pull count, and other registry metrics are collected automatically and visible in the Azure portal under Metrics. No customer configuration is needed to view platform metrics. To export metrics or enable resource logs (detailed operation logs), configure Diagnostic Settings on the registry. Phase B: Failover (planned via replica disable, or automatic via health-aware failover) Per-replica regionEndpointEnabled state via az acr replication list — confirms whether a manual disable took effect, i.e. which replicas are currently eligible for global endpoint routing. Note: this flag reflects the manual configuration for configuring a geo-replica's global endpoint routing eligibility; it does not indicate whether health-aware failover has actively rerouted traffic away from a replica. Resource Health for the registry (in the Azure portal under Help > Resource health) — surfaces platform-side degradation signals during incidents. ACR does not yet expose a definitive "this region is currently serving your traffic" signal; Resource Health and client-side latency changes are the best available indicators. Pull latency from clients — increased latency from a more distant replica is the client-observable signal that traffic has rerouted. Azure Monitor platform metrics — visible per-region in the Azure portal Metrics blade. To export metrics or query them programmatically, enable Diagnostic Settings. Phase C: Failback (replica returns to global routing) az acr replication list — confirms regionEndpointEnabled: True (manual) or online status across all replicas (automatic). Pull latency normalizing as clients reach the recovered replica again. Resource Health clearing for the registry (visible in the Azure portal). Note: The health-aware failover blog calls out ongoing work to surface richer signals — including notifications for when routing changes and which region is currently serving your traffic. The signals listed above are what's available today. Pricing Considerations Storage billing vs. storage quota: Storage is billed per geo-replica — a 1 GiB image replicated to 5 geo-replicas is charged as 5 GiB of storage (1 GiB × 5 geo-replicas). However, storage quota (the tier's maximum storage limit) counts the image only once — the same 1 GiB image counts as 1 GiB toward your tier's maximum, not 5 GiB. Data transfer: Geo-replication can reduce costs by enabling in-region image pushes and pulls, which avoids cross-region data transfer charges during these push or pull operations. However, cross-region data transfer charges still apply when ACR replicates pushed content to other geo-replicas as part of eventual consistency. Disabled replicas still cost: When you take a replica out of global routing with --global-endpoint-routing false , storage and per-replica costs continue accruing because data continues syncing bidirectionally. For more information, see ACR pricing. Cleanup Run these commands to undo the walkthrough setup. Order matters: disable regional endpoints before deleting replicas, since regional endpoint URLs depend on which replicas exist. # Disable regional endpoints if you enabled them in Step 2a az acr update -n myregistry -g myrg --regional-endpoints disabled # Re-enable any replicas you disabled in Step 3 (no-op if already enabled) az acr replication update --registry myregistry --name westus \ --global-endpoint-routing true # Delete the West US replica created in Step 1 az acr replication delete --registry myregistry --name westus # Confirm only the home region replica remains az acr replication list --registry myregistry --output table Note: Replica deletion is a control-plane operation that requires the home region to be available. During a home region outage, replica configuration cannot be modified. Summary Table Question Answer When should I use regional endpoints vs the global endpoint? Use regional endpoints (Step 2a) for workloads that need affinity, predictable routing, push/pull consistency, troubleshooting, or client-side failover. Use the global endpoint (Step 2b) for everything else and let health-aware failover handle routing. What should I enable for secure, resilient layer downloads? Enable dedicated data endpoints. They scope firewall rules tightly to your registry and replace wildcard storage DNS with predictable per-region FQDNs. How do I avoid DNS-bouncing manifest validation failures on push? Pin pushes to a single replica via a regional endpoint. A short-lived client-side dnsmasq for the push duration is also fine if you're not using regional endpoints. Should I run a long-lived DNS cache for the global endpoint? No. ACR purges DNS server-side on disable and during failover; client-side caching works against that. Do I need to re-auth when switching endpoints? Yes. Each global or regional endpoint is its own authenticated surface. az acr login , SDK auth, or the Kubernetes ACR credential provider handles the re-auth. What happens during a home region outage? Data plane keeps working through any replica via the global endpoint or regional endpoints. Control plane operations (replica configuration, network rules) are unavailable until the home region recovers. The home region is fixed at registry creation. What's ACR doing about eventual-consistency pain? Bounded staleness consistency for cross-replica pushed images is in development and will be covered in an upcoming blog post. Reach out via GitHub if you want to share your scenario. For the full automation matrix — what's automatic, what requires customer action, and what to expect for each scenario — see the behavior summary above. If you have further questions about ACR geo-replication routing, pinning, capacity planning, eventual consistency, or failover behavior, reach out to us on the Azure Container Registry GitHub repository or file feedback through the Azure portal.Now in preview: built-in MCP for Azure App Service
At Build 2026 last week, we announced the public preview of built-in MCP for Azure App Service. It does one thing, and it does it with almost no effort on your part: it turns a REST API you already host on App Service into a Model Context Protocol (MCP) server, so AI agents and assistants can call your API as a set of tools. No MCP code to write. No second service to deploy. What it does You give App Service an OpenAPI 3.x specification (JSON or YAML) describing the operations you want to expose. The platform reads that spec and generates one MCP tool per operation, then serves the MCP endpoint over streamable HTTP at a path you choose (the default is /mcp). From there, App Service handles the parts that are tedious to build yourself: MCP protocol negotiation Tool discovery, so clients can list the operations your spec exposes Hot reload of the spec when it changes Client cancellation Any MCP-compatible client can connect, including GitHub Copilot Chat, Cursor, Windsurf, and Claude Desktop. Why it matters Most teams already have the API the agent ecosystem wants to call. What they don't have is the time to wrap it in a bespoke MCP server, keep that server in sync with the API, and operate it. Built-in MCP removes that work entirely. If your REST API runs on App Service and you can produce an OpenAPI spec for it — and most web frameworks generate one for you — you're a configuration change away from an agent-ready endpoint. Built-in or custom? Built-in MCP is the fastest path when your tools map cleanly to REST operations. If you need behavior that doesn't — multi-step workflows, in-memory aggregation, MCP resources or prompts, or more than one MCP server on a single app — a custom MCP server built with an MCP SDK and deployed as your application code is still the right choice. The two approaches complement each other, and you can read more about choosing between them in the docs. Security Built-in MCP works with App Service Authentication, so MCP requests go through the same identity checks as every other route on your app, using Microsoft Entra or any OpenID Connect provider you've configured. When App Service Authentication is enabled, the platform also publishes OAuth protected-resource metadata so MCP clients can complete the OAuth flow automatically. As always, your application code is responsible for validating the bearer token on each request — and you should avoid exposing an MCP server publicly without authentication, since every published tool becomes callable once a client connects. Getting started Built-in MCP is configured through the aiIntegration property on your App Service app, and the preview supports three configuration paths: the Azure portal, the Azure CLI (az rest), and Bicep. It runs on dedicated pricing tiers, Basic or higher — it isn't supported on Free, Shared, Consumption, or Flex Consumption plans. This is a preview, and we'd love your feedback as you try it. To enable built-in MCP on your own app and connect an MCP client, head to the docs: Configure App Service built-in MCP (preview) Use App Service as a Model Context Protocol (MCP) serverClosing the AI-readiness gap with agentic modernization
Legacy debt is widening the AI-readiness gap Legacy systems and mounting tech debt aren't just slowing your AI agenda — they're quietly stealing its potential. Aging architectures, and complex, decades-old applications, databases, and infrastructure weren't designed for high performance, complex, dynamically scaling agentic workloads. The longer legacy lasts, the wider the gap between AI ambition and AI-readiness. This year at Microsoft Build 2026, we're taking our biggest step yet toward closing it. In a recent Forrester study, 94% of IT leaders ranked modernization as a top priority for their AI strategy, yet only 43% of their portfolios have been modernized on average, and only 32% are AI-ready.¹ Ambition for AI adoption is at a high, yet most are held back by the underlying legacy code, technical debt, and modernization backlog. Forrester’s data underscores it: on average, 35% of modernization projects stall due to legacy constraints, 65% cite security and compliance as the top challenge, 58% are held back by the complexity of monolithic applications, and 59% struggle with finding skilled talent to execute.¹ The result: AI initiatives that stall before they ever reach production. Modernization is a key step to move towards AI production; and it’s typically easier said than done. The growing problem is how to execute at the pace and scale that AI now demands. That’s why IT operators, architects, application owners, and developers are turning to agents to eliminate legacy toil, connect workstreams across teams, and scale their modernization efforts while customizing how they modernize. The first agentic end-to-end modernization solution that unifies IT and developer workflows Azure Copilot migration agent and GitHub Copilot modernization agent create the first agentic, end-to-end modernization solution that unifies IT and developer workflows— helping organizations close the AI-readiness gap by connecting discovery, assessment, planning, code transformation, governance, deployment, and observability into one continuous system. Built into the tools IT teams and developers already use, the solution combines estate-scale planning with GitHub-native execution, application-aware migration, broad workload coverage across apps, infrastructure, and data, and enterprise-grade privacy, security, and flexibility— so modernization becomes a governed, scalable, portfolio-level capability across teams, rather than a series of one-off projects. Building the estate-wide modernization plan Azure Copilot migration agent (public preview) brings AI to every step of estate modernization planning - from discovery and assessment to dependency mapping, ROI analysis, and wave planning - reducing months of manual analysis to minutes. For organizations with a clear picture of their estate, the migration agent accelerates the path from inventory to wave plan. For organizations that don’t, the migration agent helps them build that picture from scratch: what is running, what depends on what, what to move, what to modernize, what to retire, and in what order. By creating business-goal oriented estate plans, generating ROI analysis in minutes, and aligning IT and development teams through connected workflows, it helps enterprises move mission critical applications, databases, and infrastructure onto Azure faster and more confidently, with a continuous, data-driven view of what to modernizing next. Freeing teams from the legacy tax GitHub Copilot modernization agent, now generally available, empowers application owners, architects, and developers to scale modernization across their entire application portfolio. Operated from the CLI, the modernization agent acts as an orchestrator that simultaneously: Assesses readiness across multiple applications at once Plans application-specific modernization journeys and executes the identified migration tasks Surfaces deep code and dependency-level insights and recommendations Automates upgrades for Java and .NET applications Recommends Azure services aligned to organizational standards With its native design into GitHub Copilot, the modernization agent creates issues, pull requests, and shareable assessment reports for each application as it works. Architects and application owners retain visibility and governance from a single view, while developers receive clear, prioritized work they can execute from the agent or finish directly in their preferred editor. Behind the scenes, the modernization agent coordinates with GitHub Copilot's coding agent to complete tasks asynchronously across repositories, with a full monitoring and audit trail in GitHub's Agent HQ. The result is a connected planning-to-execution flow that finally makes modernization at scale possible, without sacrificing oversight or control. In just a few months, the modernization agent has already accelerated modernization up to 4x faster across hundreds of thousands of legacy .NET and Java applications at hundreds of customers. Enterprise level customization Every application is built and operated as uniquely as the business it serves. The path to modernization must be equally unique: tailored to each application's architecture, dependencies, and intent. At Build, we're excited to announce the general availability of custom skills for the modernization agent. Custom skills (GA) let developers teach the modernization agent how their organization works by encoding proprietary patterns, libraries, Azure best practices, and migration approaches once, then reusing them across every run. Each skill is authored as a skill.md file with build instructions, sample usage, reference APIs, and more, and is built on open-standard agent skills so teams aren't locked into a proprietary format. With custom skills, developers can equip the modernization agent with: Business-specific context, knowledge, intent, and migration approaches for application-aware guidance Centralized skills library to reuse and repeat tasks across the portfolio Full traceability for every skill used in generating the modernization plan The result is portfolio-scale execution with application-level specificity, in the same agentic workflow. And because skills live in a shared library, teams can reuse and repeat for faster, more consistent modernization outcomes aligned with the application's goals. Innovating while closing the AI-readiness gap GitHub Copilot is already dramatically reducing technical debt in real world environments, helping to close the AI readiness gap and, more importantly, innovate faster with AI. Organizations that adopt agentic modernization can not only close their AI-readiness gap, they can also make modernization a continuous process, allowing them to more readily integrate AI into existing business applications and services Ready to reimagine your applications? Join us at Microsoft Build this year, online or in person, to see our product teams reimagine applications live with GitHub Copilot modernization, share customer success, and empower you to modernize with confidence in days, not months. Join online or in person for Build session BRK220 on Wednesday 9AM PST Learn more about GitHub Copilot modernization: aka.ms/ghcp-modernization Dive deeper at the virtual .NET Agentic Modernization Day on June 16 th : aka.ms/dotnetday/rsvp ¹ Forrester’s Q1 2026 Cloud and AI Application Modernization Survey [E-66670]Announcing Public Preview of Argo CD extension in AKS Azure Portal Experience
We are excited to announce the public preview of Argo CD in the Azure Portal for Azure Kubernetes Service. As GitOps becomes the standard for deploying and operating applications at scale, customers need a way to adopt GitOps with simpler onboarding, secure defaults, and integrated workflows. With Argo CD now available directly in the Portal, teams can enable and manage GitOps without the complexity of manual setup. Bringing GitOps into the AKS experience Argo CD is widely used across Kubernetes environments, but setup often requires manual configuration across identity, networking, and registry integrations. With the Azure Portal experience, customers can: Enable Argo CD directly from the AKS cluster Configure identity, access, ingress, and registry integration in a guided flow Manage and monitor GitOps workflows through Argo CD UI This reduces onboarding friction and helps you reach your first successful GitOps deployment faster. Trusted identity and secure access The Argo CD experience integrates with Microsoft Entra ID to provide a secure, enterprise-ready foundation: Secure authentication using Workload Identity federation to Azure Container Registry (ACR) and Azure DevOps, removing long-lived credentials and hard-coded secrets Single Sign-On (SSO) using existing Azure identities Enterprise-grade hardening and security This preview includes built-in improvements to strengthen security posture: Images built on Azure Linux for reduced CVEs and improved baseline security Optional automatic patch updates to stay current while maintaining control over change management Parity with upstream Argo CD Argo CD in AKS remains aligned with the upstream open-source project, supporting: High availability (HA) configurations for production workloads Hub-and-spoke architectures for multi-cluster GitOps Application and ApplicationSet for scalable deployment across fleets Getting Started We invite you to explore the Argo CD experience in the Azure Portal and share feedback. To get started, go to your AKS cluster in the Azure Portal, navigate to the GitOps experience, and select Enable Argo CD. Follow the guided setup to configure identity, access, ingress, and registry integration with secure defaults. Once enabled, you can monitor your deployment and view application health and sync status from the Argo CD UI linked in the GitOps blade. For customers who prefer automation and scripting, the Argo CD extension is also available via Azure CLI public preview. NOTE: You can choose between Flux and Argo CD as your GitOps solution based on your needs. The Argo CD option is available during the initial GitOps setup experience, while existing Flux users will continue to see their current configuration.Don’t Start Your Application Upgrade by Changing Code
The first step of a .NET upgrade isn't code, it's assessment! That sounds obvious, but it isn't. When somebody tells you to upgrade an app, the instinct is to open the repo, bump the TargetFramework, update a few NuGet packages, and start chasing build errors, that feels like progress, but you're working without knowing what you signed up for. As we wrote at our previous posts, the Copilot modernization agent runs in three steps: assess, plan, execute. At each step it writes a Markdown file you can read and edit before it moves forward, and this time we will deep dive to learn about the assessment step! Look at the app before you touch it Jeff Fritz recorded a walkthrough of the Copilot modernization agent assessing the eShop reference app, upgrading from .NET 8 to .NET 10. The interesting part isn't that it upgrades the code. It's that it doesn't, not at first. The agent runs an assessment pass first, reading the solution, walks the dependency graph, and writes a Markdown report you can actually open and read. No commits, no `.csproj` edits. Just a file. What's in that report? In the eShop run: 10 projects that all need to move. 24 NuGet packages requiring updates, 5 of them incompatible. 52 APIs with behavioral changes that'll need testing. And every project marked "low difficulty," which tells you this particular upgrade is an afternoon, not a sprint, Knowing which project is going to be the hard one before you start changes how you plan the whole upgrade. That's what the assessment actually produced on a real codebase, and you can see it generated in about minutes with the agent running in autopilot mode in VS Code. The order matters The workflow the agent encourages is straightforward, first, assess the app as it is today, plan the upgrade based on what assessment found, lastly, implement the changes to modernize the app. The order is the whole point, if you jump straight to step three you discover the dependency conflicts and the missing test coverage live, while you're already mid-upgrade. By the time you find them, you're committed. You've already burned the easy rollback. The point to do the assessment is to move all of that to the front, when it's still cheap to change your mind. The Markdown report isn't meant to sit there untouched. You can open it, edit it, add notes, mark the projects you know are fragile, assign owners, flag the services that have a release freeze next month. Turn it into something your team will actually use to run the upgrade. Remember that Copilot doesn't know that the payments service is owned by a team that's mid-reorg, or that the reporting module is the one the CFO looks at on Monday mornings. That context still has to come from you. When you move to the planning step, the plan builds on whatever you left in that assessment. If you added constraints or flagged a project as "don't touch until Q3," that's what Copilot works from. You're setting direction, not just reviewing output. Watch it in action If you want to see the full assessment flow running on eShop, Fritz's video walks through it start to finish in VS Code with autopilot mode enabled: Modernize .NET Apps with GitHub Copilot! Test with just one app you've been putting off, run the assessment, and read the Markdown file it gives you, edit the parts that need editing, and hand it around to the two or three people who actually know that codebase. See what they push back on.
Performance Tuning and Scaling Optimization for Large-Scale Azure Workloads
Summary As cloud-native systems scale, performance challenges rarely stem from a single bottleneck. Instead, they emerge from the interaction between compute, orchestration, and data layers under load. This article captures a practical optimization journey of a high-volume Azure-based workload and highlights how controlled scaling, improved orchestration design, and proactive database maintenance can significantly outperform brute-force scaling. Introduction Distributed systems are often designed with the assumption that scaling out will solve performance issues. However, for orchestration-heavy and database-intensive workloads, this approach can introduce more problems than it solves. In this scenario, the system processed millions of transactional records through Azure Functions, Durable Functions, messaging pipelines, APIs, and SQL databases. As the workload grew, the platform began experiencing: CPU and memory spikes Slower SQL queries Service Bus throttling Increased retries and execution delays What stood out was that these issues were not due to insufficient resources, but due to inefficient execution patterns at scale. The optimization effort therefore focused on controlling how the system scaled and executed, rather than simply increasing capacity. Understanding Workload Behavior A critical early step was identifying the nature of the workload—specifically, whether it was CPU-heavy or data-heavy. Rethinking Scaling: More Is Not Always Better One of the most important lessons was that scaling out aggressively can degrade performance. As more function instances processed messages in parallel: Database calls increased sharply API traffic surged Lock contention intensified Retry rates increased This created a cascading effect where retries amplified load, further slowing down the system. To address this, scaling was intentionally controlled using: Concurrency limits on function execution Batch-based processing instead of full parallel fan-out Small delays to smooth traffic spikes Chunking of large datasets into manageable units This shift from maximum parallelism to controlled throughput significantly improved system stability. Compute Optimization: CPU and Memory After stabilizing scaling behavior, the next step was optimizing compute usage. CPU Optimization CPU spikes were largely caused by excessive parallel execution and orchestration overhead. Improvements included: Breaking large workloads into smaller units Reducing unnecessary fan-outs of processes Limiting concurrent executions This resulted in more predictable CPU usage and improved execution consistency. Memory Optimization Memory pressure was primarily driven by large payloads and batch processing. Optimizations focused on: Processing data in smaller chunks Avoiding large in-memory payloads and memory leaks Reducing orchestration state size These changes improved system reliability and reduced execution failures under load. Scaling Approaches: Practical Trade-Offs Both vertical and horizontal scaling were used, but with careful consideration. Scale Up (Vertical Scaling) Quick to implement No architectural changes required Useful for immediate stabilization However, it had cost and scalability limits. Scale Out (Horizontal Scaling) Better suited for long-term scalability Enables workload distribution But without control, it can: Increase database contention Amplify retries Introduce instability Key Insight The most effective approach was not choosing one over the other but combining both with strict control over concurrency and execution patterns. Durable Functions: Orchestration Optimization Durable Functions were central to the system, making orchestration design a key factor in performance. Challenges Observed The initial design relied heavily on nested sub-orchestrators, which introduced: High orchestration overhead Increased replay and persistence operations Slower execution at scale Key Improvements Refactoring unnecessary sub-orchestrators into Activity Functions simplified execution and improved throughput. The benefits included: Reduced orchestration latency Faster execution cycles Lower infrastructure cost Note: However, sub-orchestrators remain the right choice when the design requires composing multiple dependent steps, managing scoped retry/error logic, or isolating orchestration history. The decision should be driven by the complexity and reuse requirements of each workflow segment and not applied as a blanket rule. Improved Retry Strategy Retry behavior was also optimized by redefining execution boundaries. Previously: One activity processed multiple records A single failure triggered a retry of the entire batch After optimization: One activity handled one logical unit of work This enabled: Granular retries Better failure isolation Reduced duplicate processing Database Hygiene: A Critical Foundation The database emerged as a major bottleneck due to fragmentation and stale statistics caused by continuous high-volume operations. Issues Identified Fragmented indexes Inefficient query plans Increased query execution time Optimization Approach A proactive maintenance strategy was implemented using scheduled jobs to: Update statistics regularly Rebuild indexes Maintain query performance consistency Controlled Database Load For heavy long-running workloads in multi-tenant architecture, execution of DB intensive process was intentionally run in singleton fashion at a tenant level to reduce contention. This approach: Prevented concurrent heavy operations Improved overall system stability Delivered more predictable throughput Observability: Finding the Real Problem A major challenge during optimization was distinguishing between symptoms and root causes. For example: Slow APIs were often caused by database contention High retries were triggered by upstream throttling Orchestration delays originated from downstream dependencies To address this, end-to-end observability was established using: Application-level tracing Load testing correlations Cross-service telemetry analysis This enabled accurate root cause identification and prevented misdirected optimization efforts. Key Takeaways Some key principles emerged from this optimization journey: Scaling more does not always mean performing better Controlled parallelism is more effective than unrestricted concurrency Orchestration design directly impacts system performance Database maintenance must be proactive Retry strategies should align with logical units of work Observability is essential for correct diagnosis Conclusion Performance tuning in distributed systems is less about adding resources and more about using them efficiently. By focusing on controlled scaling, simplifying orchestration, maintaining database health, and improving observability, the system achieved higher throughput, lower cost, and significantly improved stability. These lessons are broadly applicable to any Azure-based system handling large-scale, orchestration-heavy workloads and can help teams design more predictable and resilient architectures.Explaining what GitHub Copilot Modernization can (and cannot do)
In the last post, we looked at the workflow: assess, plan, execute. You get reports you can review and the agent makes changes you can inspect. If you don’t know, GitHub Copilot Modernization is the new agentic tool that supports you to in modernizing older applications. Could it support you with that old 4.8 Framework app, even that forgotten VB.NET script? You're probably not modernizing one small app. It is probably a handful of projects, each with its own stack of blockers. Different frameworks, different databases, different dependencies frozen in time because nobody wants to touch them. GitHub Copilot modernization handles two big categories: upgrading .NET projects to newer versions and migrating .NET apps to Azure. But what does that look like? Upgrading .NET Projects Let’s say, you've got an ASP.NET app running on .NET Framework 4.8 or it's a web API stuck on .NET Core 3.1. Unfortunately, getting it to .NET 9 or 10 isn't just updating a target framework property. Here's what the upgrade workflow handles in Visual Studio: Assessment first. - The agent examines your project structure, dependencies, and code patterns. It generates an Assessment Report, which shows both the app information, to create the plan, and shows what it needs to do and update. Then planning. - Once you approve the assessment, it moves to planning. Here you get upgrade strategies, refactoring approaches, dependency upgrade paths, and risk mitigations documented in a plan.md file at .appmod/.migration, you can check and edit that Markdown before moving forward or ask in the Copilot Chat window to change it. # .NET 10.0 Upgrade Plan ## Execution Steps Execute steps below sequentially one by one in the order they are listed. 1. Validate that a .NET 10.0 SDK required for this upgrade is installed on the machine and if not, help to get it installed. 2. Ensure that the SDK version specified in global.json files is compatible with the .NET 10.0 upgrade. 3. Upgrade src\eShopLite.StoreFx\eShopLite.StoreFx.csproj ## Settings This section contains settings and data used by execution steps. ### Excluded projects No projects are excluded from this upgrade. ### Aggregate NuGet packages modifications across all projects NuGet packages used across all selected projects or their dependencies that need version update in projects that reference them Then execution. - After you approve the plan, and the agent breaks it into discrete tasks in a tasks.md file. Each task gets validation criteria. As it works, it updates the file with checkboxes and completion percentages so you can track progress. It makes code changes, verifies builds, runs tests. If it hits a problem, it tries to identify the cause and apply a fix. Go to the GitHub Copilot Chat window and type: The plan and progress tracker look good to me. Go ahead with the migration. It usually creates Git commits for each portion so you can review what changed or roll back if you need to. In case you don’t have a need for the Git commits for the change, you can ask the agent at the start to not commit anything. The agent primarily focuses on ASP.NET, ASP.NET Core, Blazor, Razor Pages, MVC, and Web API. It can also handle Azure Functions, WPF, Windows Forms, console apps, class libraries, and test projects. What It Handles Well (and What It Doesn't) The agent is good at code-level transformations: updating TargetFramework in .csproj files, upgrading NuGet packages, replacing deprecated APIs with their modern equivalents, fixing breaking changes like removed BinaryFormatter methods, running builds, and validating test suites. It can handle repetitive work across multiple projects in a solution without you needing to track every dependency manually. It's also solid at applying predefined Azure migration patterns, swapping plaintext credentials for managed identity, replacing file I/O with Azure Blob Storage calls, moving authentication from on-prem Active Directory to Microsoft Entra ID. These are structured transformations with clear before-and-after code patterns. But here's where you may need to pay closer attention: Language and framework coverage: It works with C# projects mainly. If your codebase includes complex Entity Framework migrations that rely on hand-tuned database scripts, the agent won't rewrite those for you. It also won't handle third-party UI framework patterns that don't map cleanly to ASP.NET Core conventions that have breaking changes between .NET Framework and later .NET versions. Web Forms migration is underway. Configuration and infrastructure: The agent doesn't migrate IIS-specific web.config settings that don't have direct equivalents in Kestrel or ASP.NET Core. It won't automatically set up a CI/CD pipeline or any modernization features; for that, you need to implement it with Copilot’s help. If you've got frontend frameworks bundled with ASP.NET (like an older Angular app served through MVC), you'll need to separate and upgrade that layer yourself. Learning and memory: The agent uses your code as context during the session, and if you correct a fix or update the plan, it tries to apply that learning within the same session. But those corrections don't persist across future upgrades. You can encode internal standards using custom skills, but that requires deliberate setup. Offline and deployment: There's no offline mode. The agent needs connectivity to run. And while it can help prepare your app for Azure deployment, it doesn't manage the actual infrastructure provisioning or ongoing operations, that's still on you. Guarantees: The suggestions aren't guaranteed to follow best practices. The agent won't always pick the best migration path. It won't catch every edge case. You're reviewing the work; pay attention to the results before putting it into production. What it does handle: the tedious parts. Reading dependency graphs. Finding all the places a deprecated API is used. Updating project files. Writing boilerplate for managed identity. Fixing compilation errors that follow a predictable pattern. Where to Start If you've been staring at a modernization backlog, pick one project. See what it comes up with! You don't have to commit to upgrading your entire portfolio. Try it on one project and see if it saves you time. Modernization at scale still happens application by application, repo by repo, and decision by decision. GitHub Copilot modernization just makes each one a little less painful. Experiment with it!
