Announcing Azure Database for MySQL - Flexible Server for business-critical workloads
Published May 24 2022 08:00 AM 7,621 Views

With Azure Database for MySQL – Flexible Server, we’re on a mission to enable customers to bring their MySQL workloads to Azure to unlock cost savings, make database development easy, and reduce the operational burden associated with database management, all while maintaining complete control.


Now, we’re making it easier and more cost effective for customers to run their mission-critical workloads on Azure Database for MySQL – Flexible Server with a new service tier. We’ve enhanced what was previously known as the Memory Optimized service tier with lower IO latency, higher availability, and greater scalability, and we’ve renamed it as the Business Critical service tier. This new offering is ideal for running Tier 1 mission critical MySQL workloads on Azure.


With the release of the Business Critical service tier for Azure Database for MySQL – Flexible Server, customers can deploy their MySQL databases using one of the following service tiers:

  • Burstable – Ideal for workloads that don’t constantly require 100% of the CPU, such as Dev and Test environments, CI/CD pipelines, and production workloads that only require higher compute capacity at specific times during the day; provides the greatest potential cost savings. 
  • General Purpose – Ideal for Tier 2 production workloads, this service tier balances performance and scale, offering low-to-medium concurrency.
  • Business Critical – Ideal for Tier 1 production workloads such as gaming, e-commerce, and Internet-scale applications, which require low latency, high concurrency, fast failover, and high scalability.

A summary comparison of these three tiers is shown in the following table:



General Purpose

Business Critical

Virtual Machine series





1 – 20 Burstable vCores

2 - 64 vCores

2-104 vCores

Max Memory

80 GiB

256 GiB

672 GiB

Max IOPs




Max connections




Storage size

20 GiB to 16 TiB

20 GiB to 16 TiB

20 GiB to 100 TiB

Ideal for:

Workloads that don’t require 100% of the CPU all the time

Tier 2 workloads with limited scale requirements

Tier 1 workloads requiring low latency, fast failover, & scaling

Primary motivation to use this service tier 

Cost optimization

Balanced performance, scale, and concurrency

High performance, fast failover, higher scale limits


Customers can seamlessly scale across the compute instances within a service tier without having to recreate the server by selecting the desired compute instance and then saving the configuration.


Achieve 1.5x improvement in performance compared to Single Server on open-source community MySQL engine

The Business Critical service tier achieves low latency and fast failover by placing the log file on a low latency premium managed disk, thereby significantly improving the write commit latency. Log flush operations are generally the major limiting factor for database throughput. By placing the log on low latency premium managed disk storage, the performance of the Business Critical service tier realizes an out-of-the-box improvement without increasing the cost to customers.


In addition, with auto scaling of IOPs for data up to 80K, database performance is no longer limited by the IOPs, providing a significant boost in out-of-the-box performance for end users, lowering the overhead of performance monitoring and provisioning the right IOPs limit for your server.




We compared the performance (throughput and latency) of the Business Critical service tier with the Memory Optimized tier on Single Server by using standard sysbench testing with OLTP workload with 70% reads and 30% writes on 16vCore compute instances. The Business Critical service tier provides a 1.5x improvement in performance over a similarly priced Single Server (16 vCore) compute instance. At higher concurrency, the throughput is primarily limited by the CPU capacity available on the server.


Tip: When performing sysbench testing, ensure to use a client virtual machine (VM) running sysbench with a high vCore configuration to ensure that throughput isn’t limited by the client VM CPU capacity.


2BC vs SS.jpg


Take advantage of the latest MySQL community major and minor versions available every six months

The MySQL engineering team is making significant investments in improving the performance, concurrency, and availability of the MySQL community edition with the InnoDB storage engine. With Flexible Server, we’re committed to bringing customers the latest features, community innovations, and bug fixes available in the latest major and minor version updates every six months.


Data continues to be stored in MySQL native format, which can easily be exported to ensure that customers can avoid any cloud lock-in threat. With Flexible Server’s scheduled maintenance feature, customers can maximize the server uptime for their businesses by defining a one-hour time window during off business hours to run monthly maintenance on the server.


Easily scale workloads up to 104 vCores on Azure infrastructure innovations

With the Business Critical service tier, we're adding three new compute instances: 80 vCores, 96 vCores, and 104 vCores, which will support higher scalability for mission critical workloads. 80vCore and 96vCores compute instances are generally available today, while support for 104vCores is available in limited preview. Customers’ servers run on the latest Azure Edsv5-series VMs, which use the 3rd Generation Intel® Xeon® Platinum 8370C (Ice Lake) processor that reaches an all core turbo clock speed of up to 3.5 GHz. The 104 vCores compute instance supports 672 GiB of RAM.


Maximize uptime with fast failover

Flexible Server offers multiple high availability options, including same zone and zone redundant high availability. With high availability enabled, the failover time is typically 60-120 seconds. However, using the Business Critical service tier, the typical failover time reduces to 30-60 seconds, which results from fast recovery with logs on low latency disk.


The total failover time of a MySQL flexible server can be represented using the following equation:


Total Failover time = Failure detection time + Standby recovery time + DNS switchover time (TTL)


Most of the failover time is spent in Standby recovery time to recover the logs on the standby server. With binary logs on a low latency storage disk, the commit and recovery of standby in Business Critical service tier can complete much faster, thus resulting in lower replication latency and faster failover that typically completes in 30 seconds, thereby offering better high availability.


Save cost and reduce the operational burden with auto-scaling storage up to 100 TB and IOPs up to 80K

With Flexible Server, customers no longer need to provision storage and IOPs for their workloads across the Burstable, General Purpose, and Business Critical service tiers, as this is managed automatically. With the Business Critical service tier, storage will auto-grow up to 100 TB while IOPs will scale up to 80K automatically on-demand, when queries require more IOPs to bring more data into memory or during checkpoints for data writes. Customers no longer need to provision IOPs and pay for unutilized IOPs bandwidth, providing further cost savings and improved performance out-of-the-box with reduced overhead.


Save up to 30% with additional Burstable compute instances

The Burstable service tier is ideal for workloads that don’t continuously require full CPU performance, such as small databases and development build environments. These workloads typically have burstable and auto-scaling compute performance requirements. We’re excited to announce the addition of new Burstable compute instances to support customers’ auto-scaling compute requirements from 1 vCore up to 20 vCores.


The Burstable service tier allows customers to choose a VM size with baseline performance that can accrue credits when usage is under its baseline. When the underlying compute VM has accumulated credits, it can burst above the baseline using up to 100% of the vCore capacity when applications require higher CPU performance. The Burstable service tier caters to the same scenarios as serverless, but with the advantage of providing customers with a fixed, predictable cost per hour.


Consider an office check-in/check-out application, which needs CPU bursts during business hours but doesn’t require a lot of computing power during off hours. In this example, the workload requires a 16vCPU virtual machine with 64 GiB of RAM during peak hours to work efficiently. While the current solution might be using a General Purpose 16vCore compute instance for this application, a customer can now switch to a Burstable 16 vCore compute instance, affording them a 15-20% cost savings.


To make things even easier, Flexible Server’s Azure Advisor feature available in portal provides a recommendation if the compute is a good candidate for switching to Burstable compute, which would offer instant cost savings.


Reduce restore time by 90% with on-demand backups

Beginning in July, customers will be able to take on-demand backups of the production flexible server workload, in addition to the automated backups taken by Flexible Server and store it in alignment with server’s backup retention policy. These user-initiated backups can then be used as a fastest restore point to perform a point-in-time restore to reduce restore times by up to 90% as the restore would happen from a full server backup. Azure Database for MySQL Flexible server allows you to take up to 50 on-demand backups for your server. You can trigger an on-demand backup at any point in time by navigating to the Backup and restore blade and selecting Backup now.




Encrypt data using customer managed keys (Bring Your Own Key)

Beginning in July, Azure Database for MySQL - Flexible Server will support encrypting data at rest (including any associated backups and transaction logs) using customer managed keys in public preview. Data encryption with customer-managed keys for Azure Database for MySQL - Flexible Server provides the following benefits:

  • Data-access is fully controlled by the customer, by removing the key or the access to the key, the flexible server can be rendered inaccessible.
  • Full control over the key-lifecycle, including rotation of the key to align with corporate policies.
  • Central management and organization of keys in Azure Key Vault.
  • Ability to implement separation of duties between security officers and administrators.
  • Ability to manage access to multiple flexible servers using the same user managed identity.

Customers can encrypt the data while creating a new flexible server or on an existing server without requiring any application changes. Organizations can additionally enforce data encryption with customer managed keys using built in Azure policies while creating new flexible servers. Customers can manage the keys used for encryption in Azure Key Vault, and they can manage the rights to the keys via a user assigned managed identity. Finally, organizations can take advantage of encryption using customer managed keys to implement separation of duties in the management of keys and data.


4MySQL CMK experience.png



In summary, be sure to consider the following points:

  • Azure Database for MySQL – Flexible Server makes it easy and cost effective for customers to run their MySQL workloads on Azure.
  • The Burstable service tier for Azure Database for MySQL – Flexible Server provides significant cost savings for workloads that require the ability to scale compute up to 20 vCores but that don’t continuously need 100% CPU performance
  • The Business Critical service tier for Azure Database for MySQL – Flexible Server is ideal for running Tier 1 mission critical applications with low operational burden, providing peace of mind. Use the new Business Critical service tier for your high-performance applications.

On May 24th, 2022, the Memory Optimized service tier for Azure Database for MySQL - Flexible Server is being renamed as the Business Critical service tier. The new Business Critical service tier will be generally available to customers so that they can bring and run their production workloads on Azure backed by SLAs. The new Business Critical service tier will support up to 96 vCores, IOPs scaling up to 48K, and IO latency improvements.


Existing flexible servers based on the Memory Optimized service tier will be automatically upgraded to the Business Critical service tier as part of the next scheduled maintenance window for the server. After the upgrade, existing customers will realize between 20-30% improvement in performance.


Features in limited preview

Additional Business Critical service tier features such as log placement on a low latency managed disk, 104 vCore compute instances, auto-scaling IOPs up to 80K, and storage up to 100TB will be available in limited preview and then be released publicly in coming months. For more information about Azure Database for MySQL – Flexible Server, see the service documentation.


Customers interested in enrolling in a limited preview can navigate to the Azure portal, and then, on the Compute + storage blade for their Azure Database for MySQL flexible server, select the info-box to enroll in private preview of Business Critical service tier features.




Feeback and additional resources

We look forward to hearing about customers’ experience with using the new Business Critical service tier. We’re always eager to hear customer feedback, so please reach out to us at Ask Azure DB for MySQL.


To learn more about our Flexible Server managed service, see the Azure Database for MySQL service page.

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‎May 25 2022 09:02 AM
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