When evaluating a solution, we need to define the requirements for our application around these following elements:
- High Availability (HA): Local fast and automatic failover, for high availability
- Disaster Recovery (DR): Remote fast and site level failover, for disaster recovery and continuous operations
- Zero Downtime: Perform complex system changes or routine maintenance, while keeping applications available
- Geo-Scale: Geographically distributed (active/passive or active/active) low-latency database deployments with a single consolidated management view
- Read Scale: Fast local response times for read traffic, even in a geo-distributed deployment
- Multi-Primary: Ability to deploy active MySQL clusters across multiple regions
- Transparency: No changes to application code or stack
- Flexibility: Avoid cloud or vendor lock-in
- Support: Access to 24/7 support by experienced MySQL database engineers
Welcome to the fourth blog in the “Continuent High Noon Series!” As the only complete, fully-integrated clustering solution for MySQL, we are looking at the various solutions for MySQL that provide High Availability (HA), Disaster Recovery (DR), and Geo-Scale deployments. We will dig into the requirements, features, and limitations of each solution, then rate them on such topics as performance, scalability, failover, and more!
Azure Database for MySQL Characteristics
Azure Database for MySQL is a managed database cluster within Microsoft Azure Cloud that runs MySQL community edition. There are really two deployment options: “Single Server” and “Flexible Server (Preview).” Single server is just how it sounds: a single managed MySQL instance is deployed without a standby for failover. Flexible server, which is in preview, allows failover to take place within an availability zone (using shared storage), and across availability zones (using synchronous replication). We will look at the Flexible Server version, even though it is still preview, because most enterprise applications require failover.
Some of the notable features are:
- Fully managed deployment of databases
- Point and click backups
- Automatic failover (in preview)
- Synchronous Replication for standby in another AZ (in preview)
- Encryption of data in flight and at rest
Azure Database for MySQL Cross-Region Requirements
Multi-site WAN topologies usually use asynchronous replication to be set up between clusters over a WAN. Azure MySQL allows the user to create read replicas in other regions using asynchronous replication. These read replicas naturally can be used for reads, and can be used for disaster/recovery, to fail over to another region. After failing over, the new primary instance becomes a standalone cluster.
Azure Database for MySQL Limitations
- Only a single failover candidate (in preview) or no standy
- Failover candidate cannot be used for reads, but doubles the cost when added
- Limited cross region support
- No MySQL proxy offered
- Cross region failover creates a standalone cluster — all other regions must be reprovisioned.
- Linear pricing - use 5x more instances, pay 5x more
- Application must be read/write aware
- Database maintenance and schema changes will cause application outages
Tungsten Clustering vs Azure MySQL
Continuent Tungsten Clustering is all about geo-distributed MySQL high availability on-premises, hybrid-cloud, and multi-cloud. Our customers stay with us (current average life-time 8+ years and counting), citing the completeness and maturity of the solution and the excellent, very fast (less than 3 minutes average response time) 24/7 support as reasons to choose Continuent.
The Azure MySQL and Tungsten Cluster features comparison table displays in an easy-to-view checklist each of the key elements needed to make a great MySQL HA/DR/Geo-Scale solution:
|Microsoft Azure MySQL||Tungsten Cluster|
|Management & Monitoring||4.00||4.80|
As part of our High Noon series of on-demand webinars, this webinar looks at some of the key characteristics of Azure MySQL and how it fares when compared to Continuent Tungsten Clustering.
Watch this webinar to learn about how to best build a geo-scale, multi-region and highly available MySQL, MariaDB, or Percona MySQL backend, in the cloud, hybrid-cloud, multi-cloud, or on-premises.
Reach out to see if Tungsten Clustering is a better fit than Azure MySQL for your requirements and environment!
We’ve recently introduced this new High Noon series to help demonstrate how and why customers with business-critical or mission-critical MySQL applications have grown for years with Tungsten Clustering and continue to choose it versus alternatives.