From Blobs to Insights: Your Guide to Smart Storage Lifecycle Policies
Published Sep 11 2023 12:30 AM 3,540 Views

BlobInsight: Your Deep Dive into Smart Blob Lifecycle Management

Navigating the world of blob lifecycle policies can be daunting, especially when you aim to base them on genuine usage patterns. To simplify this journey, we're introducing our insightful exploratory notebook. While it's not a direct plug-and-play solution for production, this notebook lays out the essential steps and queries to decode how your storage account interacts with data. Think of this as your compass, pointing you towards a more in-depth analysis and exploration.




Are your Azure storage bills giving you a headache? Blob lifecycle policies might just be the remedy you need. Current policies, though adept at basic tasks like auto-deleting or moving blobs based on timeframes, often miss the nuances of real usage patterns. For instance, they might overlook the blob's size.

Interestingly, the very individuals (read: DevOps Teams) entrusted with crafting these policies might not always have a clear picture of access patterns. The challenge? Developing tools that simplify blob management while trimming down storage expenses. To truly harness the power of these policies, one must delve into access patterns and the multifaceted storage cost model. For a deep dive into Azure's pricing intricacies, here's a handy link.


After diving deep into the intricacies of blob lifecycle policies and Azure's storage costs, you might be wondering how to put this knowledge into action. To bridge the gap between theory and practice, I've created a repository that showcases practical implementations of these ideas. This hands-on resource serves as a companion to this guide, helping you navigate the technical aspects with real-world examples.


Comparing Cloud Providers: Storage Solutions at a Glance

When it comes to storage, how do major cloud providers stack up against each other? Let's break it down:

Attribute Google Cloud Storage Amazon S3 Azure Blob Storage
Size No Yes No
Last Modified Date Yes Yes Yes
Last Accessed Date Yes (via Autoclass) Yes Yes (with last access time tracking enabled)
Object Age Yes Yes Yes
Storage Class Yes Yes Yes
Object Prefix Yes Yes Yes
Object Tags No Yes Yes (via blob index tags)
Versioning No Yes Yes
Automatic Transitioning Yes - Autoclass

Yes -Intelligent-Tiering

Yes - Blob life cycle Policies



A standout feature in Google Cloud is its Autoclass, a boon for users unsure of their access patterns. However, it might not be the silver bullet for all scenarios.

But here's the game-changer: Amazon S3 uniquely offers rule-setting based on blob size. This distinction might seem minor, but it can be pivotal in optimizing storage management strategies.


Azure Storage: Demystifying the Cost Model

When it comes to Azure storage, costs aren't just a factor of the data volume. They're a blend of multiple elements: the monthly data volume, the diversity and frequency of operations, the cost of data transfers, and the redundancy options you choose. Each storage tier - Hot, Cool, Cold, and Archive - comes with its own pricing structure, which encompasses data volume, operations, transfers, and redundancy.

Here's a simple breakdown:

Imagine you're working with 1TB of storage (in LRS). Here's what you might end up paying:

  • Hot Tier: Approximately $20
  • Cool Tier: Around $10
  • Cold Tier: An estimated $4.5
  • Archive Tier: Just a bit over $2

However, these aren't just static numbers based on size. They take into account operations and data transfers. So, when considering savings by transitioning between tiers, it's crucial to see beyond just the storage size. The frequency with which you access the data plays a vital role. For instance, while retrieving data is free in the Hot tier, there's an associated cost in the other tiers. Additionally, be wary of penalties incurred when switching data between tiers within specific timeframes.


Data Points: Piecing Together the Storage Puzzle

To truly understand your storage's usage patterns, relying on a singular data point isn't enough. Here's why:

  • Blob Inventory: The Blob Inventory provides a snapshot of the current state of affairs. But on its own, it's like a single piece of a jigsaw puzzle - it doesn’t reveal the complete picture of how storage is being utilized.

  • Diagnostic Logs: These logs serve as a comprehensive chronicle of all interactions with your storage accounts. While they're rich in details, they lack the inventory's meta-data.

The solution? Combine both. The inventory provides the "what", and the logs offer the "how" and "when". To optimize costs without compromising on the ability to search through logs when needed, consider archiving them in storage accounts using diagnostic settings. This strategy allows for longer storage durations and seamless access to logs.


Data Collection: Mapping the Flow of Information

Understanding your storage requires a bird's-eye view of how data flows and interacts. Let's break down the process:

The Big Picture: Picture this data flow diagram:






  1. Storage Under Surveillance: The primary storage you're monitoring.
  2. Blob Inventory Insights: The output of your blob inventory rules.
  3. Diagnostic Details: Logs at the blob level, detailing diagnostics.
  4. Periodic Data Transfer: A consistent process transferring both data sets to a shared data lake.
  5. Data Lake Destination: Your existing or designated data lake.
  6. Analysis Engine: This is where the magic happens - an analytic process merges the two data sets, unveiling the usage patterns.

Zooming into Specifics:

  • Blob Inventory: Setting up Blob Inventory rules can be done via the Azure portal or specific REST calls. This guide offers a comprehensive look at your options. At a high level, you can choose between daily or weekly capture intervals and decide between parquet or csv formats. For subsequent analysis steps, the parquet format is recommended. Additionally, to ensure efficient file sizes, consider logging only essential meta-data.

    Key Recommendations:

    • Prioritize logging only necessary schema elements.
    • Opt for weekly data captures.
    • Choose the parquet format.
    • Direct the output to a specific designated container.
  • Diagnostic Logs: You can configure these classic logs via the Azure portal. It's beneficial to hone in on the Read operation on storage, as we already have data regarding the update stamp and creation date from the inventory. Beware: logs accumulate. As of now, they can't be stored directly in your hierarchical namespace.

  • Data Transition: Given that the inventory is saved as parquet and diagnostic logs as json lines in an append_block blob type, direct access with Spark isn't feasible. Hence, there's a need to transition logs to an adls-gen2 account. During this shift, converting the json lines to parquet is a smart move. How to achieve this? Options include:

    • Azure Data Factory
    • Azure Functions
    • Python notebook

    For this guide, we'll lean on Azure Data Factory, focusing on a copy activity with json as the source and parquet as the sink. This example assumes a one-time analysis. For recurring assessments, consider automating the copy-delete process for logs from the original storage.


Essential Tools: Powering the Storage Analysis

When it comes to analyzing and managing your storage data, having the right tools in your arsenal is crucial. Here's what we recommend and why:

  • Azure Data Factory: Think of this as your data's chauffeur. Data Factory is instrumental in transporting both data sets to the data lake. Why choose it? It's a no-code solution that's perfect for one-off data movements, making the process smooth and straightforward.

  • Azure Databricks: Once your data is in place, Databricks takes the lead. It's your go-to for all data analytics tasks. The reason it stands out? Its operational simplicity allows you to scale down your spark cluster when needed. You can even run your analytics on a single node cluster, making it efficient and cost-effective.

In essence, while Data Factory moves your data seamlessly, Databricks dives deep into it, extracting valuable insights and patterns.



Setting Off: Your Starter Guide to Optimized Storage

Diving into the world of storage optimization can seem daunting, but with the right roadmap, it becomes a seamless journey. Here's a practical blueprint to guide you:

1. Preparing Your Data:

  • Diagnostic Logs Activation: Start by turning on your diagnostic logs. A comprehensive understanding of your blob's access patterns requires data spanning a significant duration. While a month offers a basic snapshot, extending to 3 or 6 months provides richer insights, especially when considering policies that stretch beyond 30 days.
  • Blob Inventory Initialization: After securing a substantial log history, it's time to activate the Blob Inventory.

2. Navigating Data Movement:

  • Your chosen tool, be it Azure Data Factory or another, should seamlessly integrate both data sets (logs and inventory) within the same data lake, with both stored as parquet files.

3. Analyzing with Precision:

  • Launch an Azure Databricks workspace. If you're new to this, initiating with a single node cluster is ideal. Import the notebook from this repository to set the stage. From there, the notebook guides you through a thorough analysis, step by step.

Embarking on this journey, always remember: while these are your first steps, they lay the foundation for a deeper exploration into efficient and cost-effective storage strategies.


Wrapping Up: Customized Policies for Unique Storage Needs

No two storage accounts are identical, and neither should their management strategies be. While the tools and guides provided here offer a solid foundation, they're merely the starting line. With the insights from the Databricks notebook, you'll not only gain a deeper understanding of how your storage is accessed but also be empowered to craft policies tailored to your unique usage patterns.

A word of caution: while this guide and notebook serve as invaluable tools, they come 'as is'. Think of them less as a final solution and more as a launchpad – propelling you towards more nuanced analysis and tailored strategies for your storage needs.


Parting Thoughts: The Future of Blob Lifecycle Policies

As we delve deeper into the nuances of blob lifecycle policies, one glaring gap emerges: the current absence of size-based criteria in Azure's blob lifecycle policies. When blobs show similar access patterns but differ drastically in size, this can become a significant oversight, potentially impacting cost savings.

For instance, imagine two blobs. One is large, the other small. Both might be accessed with the same frequency, but the costs associated with storing the larger blob are notably higher. In such scenarios, it could be more beneficial to create a container exclusively for larger blobs and design distinct policies tailored to them, instead of applying a one-size-fits-all policy that might not optimize costs for smaller-sized blobs.

As the cloud storage landscape evolves, there's hope that future iterations of Azure's blob lifecycle policies will incorporate size-based criteria. Until then, it's up to us to think outside the box, harness the tools available, and craft policies that truly resonate with our unique storage needs. If you're looking for a hands-on approach to implementing these strategies, explore this repository for practical demonstrations and examples.



A special thanks to @OlgaMolocenco Olga Molocenco for her invaluable contributions during the research phase. Her insights and expertise greatly enriched this guide.
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‎Sep 20 2023 07:33 AM
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