Intro to PECL/mysqlnd_ms (4/7/2011)
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This document by Chris Barber introduces mysqlnd, a PHP extension replacing libmysql for PHP 5.3+, and mysqlnd_ms, which provides transparent MySQL load balancing across master and slave servers. It outlines configuration steps, usage examples, and server selection algorithms, including handling issues like transaction management and implementing failover strategies. The document also covers hints and customizations for server picking, as well as installation instructions for mysqlnd_ms.
![mysqlnd_ms_config.ini
[myapp]
master[]=192.168.1.120
slave[]=192.168.1.121
slave[]=192.168.1.122](https://image.slidesharecdn.com/2011-04-07-introtopecl-mysqlndms-110408003854-phpapp01/85/Intro-to-PECL-mysqlnd_ms-4-7-2011-10-320.jpg)
![Choosing a server
[myapp]
master[]=192.168.1.120
slave[]=192.168.1.121
slave[]=192.168.1.122
pick[]=user
pick[]=random
<?php
function pick_server($connected_host, $query, $master, $slaves, $last_used_connection) {
if (stristr($query, “FROM table_a”))
return “hostname_of_slave_for_table_a”;
return NULL; // resort to random/random-once/round-robin
}
mysqlnd_ms_set_user_pick_server(“pick_server”);
?>](https://image.slidesharecdn.com/2011-04-07-introtopecl-mysqlndms-110408003854-phpapp01/85/Intro-to-PECL-mysqlnd_ms-4-7-2011-14-320.jpg)
![Custom Hints
<?php
function pick_server($connected_host, $query, $master, $slaves, $last_used_connection) {
if (preg_match("@^/*.+*/@ismU", $query, $matches)) {
$json = json_decode($matches[1])
if ($json && $json->something_enabled) {
return “some_special_hostname”;
}
}
return NULL; // resort to random/random-once/round-robin
}
mysqlnd_ms_set_user_pick_server(“pick_server”);
$db->query(“/* {“something_enabled”:true} */SELECT ...”);
?>](https://image.slidesharecdn.com/2011-04-07-introtopecl-mysqlndms-110408003854-phpapp01/85/Intro-to-PECL-mysqlnd_ms-4-7-2011-20-320.jpg)
Intro to PECL/mysqlnd_ms (4/7/2011)
- 1. Intro to PECL/mysqlnd_ms Chris Barber Minnesota PHP User Group April 7, 2011
- 2. About Me Chris Barber Lead Software Engineer @ Appcelerator CEO/Technology Consultant @ CB1, INC. JavaScript, PHP, C++ http://www.cb1inc.com @cb1kenobi on Twitter, Slideshare
- 4. What is mysqlnd? MySQL Native Driver for PHP PHP 5.3+ Replaces libmysql Used by ext/mysql, ext/mysqli, PDO_MYSQL Use configure options: --with-mysql=mysqlnd --with- mysqli=mysqlnd --with-pdo-mysql=mysqlnd Not compiled into Ubuntu’s PHP 5.3 package :(
- 6. What is mysqlnd_ms? A PHP Extension that provides transparent MySQL load balancing across master and slave servers
- 7. How it works Create a mysqlnd_ms_config.ini with your settings Make MySQL calls from your PHP code INSERT, UPDATE, & DELETE statements go to master SELECT statements go to slaves
- 10. mysqlnd_ms_config.ini [myapp] master[]=192.168.1.120 slave[]=192.168.1.121 slave[]=192.168.1.122
- 11. PHP Usage <?php $db = mysqli(“myapp”, “user”, “password”); $results = $db->query(“SELECT ...”); $db->query(“INSERT ...”); ?>
- 12. Which server to connect to?
- 13. Choosing a server Available load balancing algorithms: random round-robin user defined (custom PHP function) random_once (sticky) Specify algorithm in the mysqlnd_ms_config.ini file
- 14. Choosing a server [myapp] master[]=192.168.1.120 slave[]=192.168.1.121 slave[]=192.168.1.122 pick[]=user pick[]=random <?php function pick_server($connected_host, $query, $master, $slaves, $last_used_connection) { if (stristr($query, “FROM table_a”)) return “hostname_of_slave_for_table_a”; return NULL; // resort to random/random-once/round-robin } mysqlnd_ms_set_user_pick_server(“pick_server”); ?>
- 15. Issues...
- 16. Issues INSERT and immediate SELECT Replication lag Transactions Need server stickiness Failover
- 17. Hints Prefix query with a comment! <?php $db = mysqli(“myapp”, “user”, “password”); $results = $db->query(“/* HINT_GOES_HERE */SELECT ...”); ?>
- 18. Built-in Hints MYSQLND_MS_MASTER_SWITCH MYSQLND_MS_SLAVE_SWITCH MYSQLND_MS_LAST_USED_SWITCH MYSQLND_MS_ALL_SERVER_SWITCH MYSQLND_MS_QUERY_USE_MASTER MYSQLND_MS_QUERY_USE_SLAVE MYSQLND_MS_QUERY_USE_LAST_USED
- 19. Hints <?php $db->query(sprintf(“/*%s*/SET @a=1”, MYSQL_MS_SLAVE_SWITCH)); $db->query(sprintf(“/*%s*/SET @a=@a+1”, MYSQL_MS_LAST_USED_SWITCH)); $db->query(sprintf(“/*%s*/SELECT @a as _a”, MYSQL_MS_LAST_USED_SWITCH)); ?>
- 20. Custom Hints <?php function pick_server($connected_host, $query, $master, $slaves, $last_used_connection) { if (preg_match("@^/*.+*/@ismU", $query, $matches)) { $json = json_decode($matches[1]) if ($json && $json->something_enabled) { return “some_special_hostname”; } } return NULL; // resort to random/random-once/round-robin } mysqlnd_ms_set_user_pick_server(“pick_server”); $db->query(“/* {“something_enabled”:true} */SELECT ...”); ?>
- 21. Server Picking Ideas Geo-load balancing Routing around server maintenance Sharding Dynamically add/override master/slave hostnames
- 22. Failover mysqlnd_ms does not do failover Do it in your application! Retry query N number of times before falling on sword Have pick_server() “disable” dead servers for a minute Perhaps use APC to cache which servers are dead
- 23. Getting mysqlnd_ms svn co http://svn.php.net/repository/pecl/mysqlnd_ms/ trunk mysqlnd_ms cd mysqlnd_ms phpize configure make sudo make install
- 24. More Info Authors: Andrey Hristov, Ulf Wendel, & Johannes Schlueter http://blog.ulf-wendel.de http://svn.php.net/viewvc/pecl/mysqlnd_ms