Best practices for server operations on Azure Database for MySQL - Flexible Server

APPLIES TO: Azure Database for MySQL - Single Server Azure Database for MySQL - Flexible Server


Azure Database for MySQL single server is on the retirement path. We strongly recommend that you upgrade to Azure Database for MySQL flexible server. For more information about migrating to Azure Database for MySQL flexible server, see What's happening to Azure Database for MySQL Single Server?

Learn about the best practices for working with Azure Database for MySQL flexible server. As we add new capabilities to the platform, we will continue to focus on refining the best practices detailed in this section.

Azure Database for MySQL flexible server operational guidelines

The following are operational guidelines that should be followed when working with Azure Database for MySQL flexible server to improve the performance of your database:

  • Co-location: To reduce network latency, place the client and the database server in the same Azure region.

  • Monitor your memory, CPU, and storage usage: You can set up alerts to notify you when usage patterns change or when you approach the capacity of your deployment, so that you can maintain system performance and availability.

  • Scale up your DB instance: You can scale up when you are approaching storage capacity limits. You should have some buffer in storage and memory to accommodate unforeseen increases in demand from your applications. You can also enable the storage autogrow feature 'ON' just to ensure that the service automatically scales the storage as it nears the storage limits.

  • Configure backups: Enable local or geo-redundant backups based on the requirement of the business. Also, you modify the retention period on how long the backups are available for business continuity.

  • Increase I/O capacity: If your database workload requires more I/O than you have provisioned, recovery or other transactional operations for your database will be slow. To increase the I/O capacity of a server instance, do any or all of the following:

  • Scale compute: Database workload can also be limited due to CPU or memory and this can have serious impact on the transaction processing. Note that compute (pricing tier) can be scaled up or down between General Purpose or Memory Optimized tiers only.

  • Test for failover: Manually test failover for your server instance to understand how long the process takes for your use case and to ensure that the application that accesses your server instance can automatically connect to the new server instance after failover.

  • Use primary key: Make sure your tables have a primary or unique key as you operate on the Azure Database for MySQL flexible server instance. This helps in a lot taking backups, replica etc. and improves performance.

  • Configure TTL value: If your client application is caching the Domain Name Service (DNS) data of your server instances, set a time-to-live (TTL) value of less than 30 seconds. Because the underlying IP address of a server instance can change after a failover, caching the DNS data for an extended time can lead to connection failures if your application tries to connect to an IP address that no longer is in service.

  • Use connection pooling to avoid hitting the maximum connection limitsand use retry logic to avoid intermittent connection issues.

  • If you are using replica, use ProxySQL to balance off load between the primary server and the readable secondary replica server. See the setup steps here.

  • When provisioning the resource, make sure you enabled the autogrow for your Azure Database for MySQL flexible server instance. This doesn't add any extra cost and protects the database from any storage bottlenecks that you might run into.

Using InnoDB with Azure Database for MySQL flexible server

  • If using ibdata1 feature, which is a system tablespace data file cannot shrink or be purged by dropping the data from the table, or moving the table to file-per-table tablespaces.

  • For a database greater than 1 TB in size, you should create the table in innodb_file_per_table tablespace. For a single table that is larger than 1 TB in size, you should the partition table.

  • For a server that has a large number of tablespace, the engine startup will be very slow due to the sequential tablespace scan during Azure Database for MySQL flexible server startup or failover.

  • Set innodb_file_per_table = ON before you create a table, if the total table number is less than 500.

  • If you have more than 500 tables in a database, then review the table size for each individual table. For a large table, you should still consider using the file-per-table tablespace to avoid the system tablespace file hit max storage limit.


For tables with size less than 5GB, consider using the system tablespace

   CREATE TABLE tbl_name ... *TABLESPACE* = *innodb_system*;
  • Partition your table at table creation if you have a very large table might potentially grow beyond 1 TB.

  • Use multiple Azure Database for MySQL flexible server instances and spread the tables across those servers. Avoid putting too many tables on a single server if you have around 10000 tables or more.

Next steps