Ulf Wendel

1.1.2-*stable* release of the replication and load balancing plugin for PHP!

PECL/mysqlnd 1.1.2-stable has been released. The mysqlnd replication and load balancing plugin for PHP 5.3/5.4 finally got the download label it deserves: stable, ready for production use! PECL/mysqlnd_ms makes using any kind of MySQL database cluster easier.

Key features

The release motto of the 1.1 series is “cover MySQL Replication basics with production quality”, which shows that the plugin is optimized for supporting MySQL replication cluster. But with its feature set it is not limited to. MySQL Cluster users will also profit from it.

  • Automatic read/write splitting
    • can be controlled with SQL hints
    • can be replaced providing callback
    • can be disabled for MySQL Cluster use
  • Load Balancing
    • random (pick for every statement or once per request, latter is default)
    • round robin (iterate per statement)
    • can be replaced providing callback
    • can be controlled with SQL hint
  • Fail over
    • optional, automatic connect fail over
  • Connection pooling
    • Lazy connections (don’t open before use, default)

The plugin can be used with any PHP MySQL API/extension (mysql, mysqli, PDO_MySQL), if the extension is compiled to use the mysqlnd library. Whatever framework, whatever API you use, it should work out-of-the box. As a library plugin, it operates on its own layer below your application. No or very little application-level changes are required.

PECL/mysqlnd_ms 1.1.1-beta in production use at ihigh.com

Nicholas Solon from ihigh.com, a US high school sports sites contacted us a couple of months ago. We have been very pleased about this. Real-life feedback – feature requests and bug reports – are most welcome. Below is an excerpt from his last mail…

We are finally running 1.1.1-beta from the latest tarball on PHP 5.3.8 with MySQL 5.5.15 on 1 master, 2 slaves (FreeBSD) and using exclusively InnoDB. It’s a production environment, so we’ve been very slow to get this set up, but I’m very pleased with the performance! In this setup, we get about 1.5 million monthly uniques according to Google Analytics. We broadcast live high school sporting events around the US and other parts of the world, so Friday nights are especially load-intense.
(Nicholas Solon, developer at ihigh.com)

From 1.0 to 1.1

The 1.1 version has been significantly re-factored and extended. Many pitfalls on connection state changes have been removed. Connection state changes can happen when switching from one cluster node to another, either for load balancing or for read-write splitting. If you are new to developing software for MySQL replication clusters, please check the concepts section of the manual.

The plugins configuration format is now JSON-based. This was done to prepare for hierarchical and nested configurations. A new filter concept has been introduced. Filters works like small Unix utilities which can be stacked. The manual, which has been extended significantly, explains both in great depth. If you prefer blog posts, check out Replication plugin | filter | conquer = 1.1.0 coming.

What’s next?

Tell us! With the 1.1.0 series we have laid necessary foundations in the code base. From here, we can drive in many directions . We can start to look into Global Transaction IDs, coming to the server soon, or we look into replication table filter rule support, or we refine load balancing rules, or….

A minor, though time-intensive thing we are planning is updating the PHP MySQL documentation.

Happy hacking!

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