At Ignite, we announced the preview of a new deployment option for Azure Database for PostgreSQL: Flexible Server. Flexible Server is the result of a multi-year Azure engineering effort to deliver a reimagined database service to those of you who run Postgres in the cloud. Over the past several years, our Postgres engineering team has had the opportunity to learn from many of you about your challenges and expectations around the Single Server deployment option in Azure Database for PostgreSQL. Your feedback and our learnings have informed the creation of Flexible Server.
If you are looking for a technical overview of what Flexible Server is in Azure Database for PostgreSQL—and what the key capabilities are, let’s dive in.
Flexible server is architected to meet requirements for modern apps
Our Flexible Server deployment option for Postgres is hosted on the same platform as Azure Database for PostgreSQL - Hyperscale (Citus), our deployment option that scales out Postgres horizontally (by leveraging the Citus open source extension to Postgres).
Flexible Server is hosted in a single-tenant Virtual Machine (VM) on Azure, on a Linux based operating system that aligns naturally with the Postgres engine architecture. Your Postgres applications and clients can connect directly to Flexible Server, eliminating the need for redirection through a gateway. The direct connection also eliminates the need to include @servername suffix in your username on Flexible Server. Additionally, you can now place Flexible Server’s compute and storage—as well as your application—in the same Azure Availability Zone, resulting in lower latency to run your workloads. For storage, our Flexible Server option for Postgres uses Azure Premium Managed Disk. In the future, we will provide an option to use Azure Ultra SSD Managed Disk. The database and WAL archive (WAL stands for write ahead log) are stored in zone redundant storage.
There are numerous benefits of using a managed Postgres service, and many of you are already using Azure Database for PostgreSQL to simplify or eliminate operational complexities. With Flexible Server, we’re improving the developer experience even further, as well as providing options for scenarios where you want more control of your database.
A developer-friendly managed Postgres service
For many of you, your primary focus is your application (and your application’s customers.) If your application needs a database backend, the experience to provision and connect to the database should be intuitive and cost-effective. We have simplified your developer experience with Flexible Server on Azure Database for PostgreSQL, in few key ways.
- Intuitive and simplified provisioning experience. To provision Flexible Server, some of the fields are automatically filled based on your profile. For example, Admin username and password use defaults but you can always overwrite them.
- Simplified CLI experience. For example, it’s now possible to provision Flexible Server inside a virtual network in one command, and the number of keystrokes for the command can be reduced by using local context. For more details, see Flexible server CLI reference.
- Connection string requirement. The requirement to include @servername suffix in the username has been removed. This allows you to connect to Flexible Server just like you would to any other PostgreSQL engine running on-premise or on a virtual machine.
- Connection management: Pgbouncer is now natively integrated to simplify PostgreSQL connection pooling.
- Burstable compute: You can optimize cost with lower-cost, burstable compute SKUs that let you pay for performance only when you need it.
- Stop/start: Reduce costs with the ability to stop/start the Flexible Server when needed, to stop a running service or to start a stopped Service. This is ideal for development or test scenarios where it’s not necessary to run your database 24x7. When Flexible Server is stopped, you only pay for storage, and you can easily start it back up with just a click in the Azure portal.
Screenshot from the Azure Portal depicting how to start compute for your Azure Database for PostgreSQL flexible server, when you’re ready to restart work.
Maximum database control
Flexible Server brings more flexibility and control to your managed Postgres database, with key capabilities to help you meet the needs of your application.
- Scheduled maintenance: Enterprise applications must be available all the time, and any interruptions during peak business hours can be disruptive. Similarly, if you’re a DBA who is running a long transaction—such as a large data load or index create/rebuild operations—any disruption will abort your transaction prematurely. Some of you have asked for the ability to control Azure maintenance windows to meet your business SLAs. Flexible Server will schedule one maintenance window every 30 days at the time of your choosing. For many customers, the system-managed schedule is fine, but the option to control is helpful for some mission-critical workloads.
- Configuration parameters: Postgres offers a wide range of server parameters to fine tune the database engine performance, and some of you want similar control in a managed service as well. For example, there is sometimes a need to mimic the configuration you had on-premises or in a VM. Flexible Server has enabled control over additional server parameters, such as Max_Connections, and we will add even more by Flexible Server GA.
- Lower Latency: To provide low latency for applications, some of you have asked for the ability to co-locate Azure Database for PostgreSQL and your application in physical proximity (i.e. the same Availability Zone). Flexible Server provides the ability to co-locate the client, database, and storage for lower latency and improved out-of-the-box performance. Based on our internal testing and customer testimonials, we are seeing much better out-of-the-box performance.
- Network Isolation: Some of you need the ability to provision servers with your own VNet or subnet, to ensure complete lock down from any outside access. With Flexible Server private endpoints, you can completely isolate the network by preventing any public endpoint to exist for the database workload. All connections to the server on public or private endpoints are secured and encrypted by default with SSL/TLS v1.2.
Zone-redundant high availability
With the new Flexible Server option for Azure Database for PostgreSQL, you can choose to turn on zone redundant high availability (HA). If you do, our managed Postgres service will spin up a hot standby with the exact same configuration, for both compute and storage, in a different Availability Zone. This allows you to achieve fast failover and application availability should the Availability Zone of the primary server become unavailable.
Any failure on the primary server is automatically detected, and it will fail over to the standby which becomes the new primary. Your application can connect to this new primary with no changes to the connection string.
Zone redundancy can help with business continuity during planned or unplanned downtime events, protecting your mission-critical databases. Given that the zone redundant configuration provides a full standby replica server, there are cost implications, and zone redundancy can be enabled or disabled at any time.
Get started with Flexible Server today!
We can’t wait to see how you will use our new Flexible Server deployment option that is now in preview in Azure Database for PostgreSQL. If you're ready to try things out, here are some quickstarts to get you started:
- Create an Azure Database for PostgreSQL Flexible Server using Azure portal
- Create an Azure Database for PostgreSQL Flexible Server using Azure CLI
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Create an Azure Database for PostgreSQL Flexible Server using ARM template
Azure Database for PostgreSQL Single Server remains the enterprise ready database platform of choice for your mission-critical workloads, until Flexible Server reaches GA. For those of you who want to migrate over to Flexible Server, we are also working to provide you a simplified migration experience from Single Server to Flexible Server with minimal downtime.
If you want to dive deeper, the new Flexible Server docs are a great place to roll up your sleeves, and visit our website to learn more about our Azure Database for PostgreSQL managed service. We are always eager to hear your feedback so please reach out via email using Ask Azure DB for PostgreSQL.
Sunil Agarwal
Twitter: https://twitter.com/s_u_n_e_e_l