SQL injection is wonderful! MySQL Proxy can do it, mysqlnd plugins - even written in PHP (not Lua or C) - can do it. Global Transaction IDs are wonderful. A mashup of the PHP replication plugin and global transaction ID injection, makes your replication cluster fail-over much smoother and opens up an opportunity for an API to support consistent reads from slaves "immediately" after a write. Less hassle identifying and promoting a new master for fail-over, even better read load balancing - my last proposal for the future of the PHP …

While Andrey is busy implementing partitioned replication infrastructure code for the PHP replication and load balancing plugin (PECL/mysqlnd_ms), I continued my search for ideas to steal. Mr. Robert Hodges, I’ve robbed the idea of a service level and caching.. If an application is able to function with stale data read from a MySQL replication slave, it can also deal with stale data from a local cache. The replication plugin (PECL/mysqlnd_ms) could, in certain cases, populate the query cache plugin (PECL/mysqlnd_qc) for you and read replies from it.

In the blog posting " …

While Andrey is busy implementing partitioned replication infrastructure code for the PHP replication and load balancing plugin (PECL/mysqlnd_ms), I continued my search for ideas to steal. Mr. Robert Hodges, I’ve robbed the idea of a service level and caching.. If an application is able to function with stale data read from a MySQL replication slave, it can also deal with stale data from a local cache. The replication plugin (PECL/mysqlnd_ms) could, in certain cases, populate the query cache plugin (PECL/mysqlnd_qc) for you and read replies from it.

In the blog posting " …

The Mysqlnd replication and load balancing plugin alpha release has focused on laying foundations for read-write splitting and load balancing. Thus, we can now look into more juicy topics such as support of schemata based partitioning to increase the granularity of load balancing. Not every slave server needs to replicate all schemata (databases) and tables of the master. The plugin load balancer shall be aware of it and transparently pick the server which has the entities required to execute a statement. Some brainstorming…

The Mysqlnd replication and load balancing plugin alpha release has focused on laying foundations for read-write splitting and load balancing. Thus, we can now look into more juicy topics such as support of schemata based partitioning to increase the granularity of load balancing. Not every slave server needs to replicate all schemata (databases) and tables of the master. The plugin load balancer shall be aware of it and transparently pick the server which has the entities required to execute a statement. Some brainstorming…

The PHP replication and load balancing mysqlnd plugin as been released as an alpha through PECL. Alpha is for those who want to try out the 1.0 feature set as early as possible. Alpha is for those who do not fear debugging, if need be. Notes on troubleshooting.

Testing load balancing and read/write split

There are three ways to verify that load balancing and read/write split works as it should:

• within PHP script: checking thread/connection ids
• within PHP script: monitoring statistics
• externally: mysqlnd debug log file

Thread/connection ids to distinguish connections

PECL/mysqlnd_ms changes the semantics of a PHP MySQL connection handle. If using the plugin, a connection handle returned by any of the three PHP MySQL extensions ( …

The PHP replication and load balancing mysqlnd plugin as been released as an alpha through PECL. Alpha is for those who want to try out the 1.0 feature set as early as possible. Alpha is for those who do not fear debugging, if need be. Notes on troubleshooting.

Testing load balancing and read/write split

There are three ways to verify that load balancing and read/write split works as it should:

• within PHP script: checking thread/connection ids
• within PHP script: monitoring statistics
• externally: mysqlnd debug log file

Thread/connection ids to distinguish connections

PECL/mysqlnd_ms changes the semantics of a PHP MySQL connection handle. If using the plugin, a connection handle returned by any of the three PHP MySQL extensions ( …

Replication is as old as life on earth. No life without replication. MySQL replication is as old as MySQL, almost. No MySQL without replication. The PECL/mysqlnd_ms 1.0.0 alpha release is brand new. My dream, no PHP without the mysqlnd library replication and load balancing plugin, which works with all the PHP MySQL extensions (mysql, mysqli, PDO_MySQL)!

PECL/mysqlnd_ms (download alpha release) is a transparent plugin for the mysqlnd library. It …

Replication is as old as life on earth. No life without replication. MySQL replication is as old as MySQL, almost. No MySQL without replication. The PECL/mysqlnd_ms 1.0.0 alpha release is brand new. My dream, no PHP without the mysqlnd library replication and load balancing plugin, which works with all the PHP MySQL extensions (mysql, mysqli, PDO_MySQL)!

PECL/mysqlnd_ms (download alpha release) is a transparent plugin for the mysqlnd library. It …

PECL/mysqlnd_ms is now transaction aware, sometimes. A new experimental configuration option trx_stickiness=master disables load balancing if autocommit mode is turned off via API. This makes the mysqlnd library plugin transaction safe. Unfortunately it requires PHP 5.3.99 and, it can be fooled by using SQL to control autocommit. It requires some discipline to use.

Past and today: SQL hints for transactions

By default the PHP replication and load balancing plugin (mysqlnd_ms) is not transaction safe, because it is not transaction aware. The plugin does not know when a transaction starts and when it ends. Thus, it may decide to load balance statements and switch connections in the middle of a transaction. So far, SQL hints have been the only way to prevent …