Ulf Wendel: The performance penalty of the early MySQL Fabric support for PHP

In his latest post Ulf Wendel looks at the performance issues around the recently introduced MySQL Fabric support included in the mysqlnd extension.

PECL/mysqlnd_ms 1.6 is currently being modified to support sharding and fully automatic server and client failover when using MySQL Fabric (slides) to manage a farm of MySQL servers. PECL/mysqlnd_ms is a mostly transparent load balancer that works with all PHP MySQL APIs (PDO_MySQL, mysqli, …). The idea is, that if, for example, a MySQL server fails, the plugin talks to MySQL Fabric to learn about alternative servers that Fabric has provisioned automatically. This "talks to" gives implies a performance penalty for applications.

He takes a look at what's happening "behind the scenes" when it comes to using the Fabric functionality and sharding (based on the use of mysqlnd_ms_select_shard). He traces through the execution path and how much slower then end result is. He includes some results from the connection debugging and the number of queries a single request makes.

Link: http://blog.ulf-wendel.de/2014/the-performance-penalty-of-the-early-mysql-fabric-support-for-php/