MySQL Fabric

MySQL Farbic is an integrated framework for managing farms of MySQL servers with support for both high-availability and sharding. Alfa in autum 2013, although there is GA release now, this is still early stage of project. It cannot be considered as a solution for production. The central concept to handling high-availability in Fabric are the high-availability groups. These are collections of servers that shall work together to deliver a database service to the application that connects. The groups are introduced to give structure to the farm and allow you to describe how the servers are organized to support the redundancy necessary to ensure high-availability. To manage redundancy, a traditional Master-Slave Setup is used. Each group have a primary that is is the master for all the data. Any queries that update data is sent here and that data is propagated to the other servers in the group. Redundancy is achieved by keeping one or more secondaries in the group that receive changes from the primary and are ready to take over the role as primary should the primary dissapear. In addition to high-availability support, MySQL Fabric also offer support for sharding.

Limitations

• Sharding is not completely transparent to the application. While the application need not be aware of which server stores a set of rows and it doesn’t need to be concerned when that data is moved, it does need to provide the sharding key when accessing the database.

• All transactions and queries need to be limited in scope to the rows held in a single shard, together with the global (non-sharded) tables. For example, Joins involving multiple shards are not supported.

• Because the connectors perform the routing function, the extra latency involved in proxy-based solutions is avoided but it does mean that Fabric-aware connectors are required – at the time of writing these exist for PHP, Python and Java

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