Oracle 5.0 Reference Manual page 2566

• PECL/mysqlnd_uh - User Handler plugin.
20.7.5.7.1. A comparison of mysqlnd plugins with MySQL Proxy
Copyright 1997-2012 the PHP Documentation Group. [2230]
plugins and MySQL Proxy are different technologies using different approaches. Both are
Mysqlnd
valid tools for solving a variety of common tasks such as load balancing, monitoring, and performance
enhancements. An important difference is that MySQL Proxy works with all MySQL clients, whereas
plugins are specific to PHP applications.
mysqlnd
As a PHP Extension, a
rest of PHP. MySQL Proxy can either be run on the PHP application server or can be installed on a
dedicated machine to handle multiple PHP application servers.
Deploying MySQL Proxy on the application server has two advantages:
1. No single point of failure
2. Easy to scale out (horizontal scale out, scale by client)
MySQL Proxy (and
changes to existing applications.
However, MySQL Proxy does have some disadvantages:
• MySQL Proxy is a new component and technology to master and deploy.
• MySQL Proxy requires knowledge of the Lua scripting language.
MySQL Proxy can be customized with C and Lua programming. Lua is the preferred scripting language
of MySQL Proxy. For most PHP experts Lua is a new language to learn. A
written in C. It is also possible to write plugins in PHP using PECL/mysqlnd_uh.
MySQL Proxy runs as a daemon - a background process. MySQL Proxy can recall earlier decisions,
as all state can be retained. However, a
PHP. MySQL Proxy can also share one-time computed results among multiple application servers. A
plugin would need to store data in a persistent medium to be able to do this. Another daemon
mysqlnd
would need to be used for this purpose, such as Memcache. This gives MySQL Proxy an advantage in
this case.
MySQL Proxy works on top of the wire protocol. With MySQL Proxy you have to parse and reverse
engineer the MySQL Client Server Protocol. Actions are limited to those that can be achieved by
manipulating the communication protocol. If the wire protocol changes (which happens very rarely)
MySQL Proxy scripts would need to be changed as well.
plugins work on top of the C API, which mirrors the
Mysqlnd
C APIs. This C API is basically a wrapper around the MySQL Client Server protocol, or wire protocol,
as it is sometimes called. You can intercept all C API calls. PHP makes use of the C API, therefore you
can hook all PHP calls, without the need to program at the level of the wire protocol.
implements the wire protocol. Plugins can therefore parse, reverse engineer, manipulate and
Mysqlnd
even replace the communication protocol. However, this is usually not required.
As plugins allow you to create implementations that use two levels (C API and wire protocol), they
have greater flexibility than MySQL Proxy. If a
subsequent changes to the wire protocol do not require changes to the plugin itself.
20.7.5.7.2. Obtaining the mysqlnd plugin API
Copyright 1997-2012 the PHP Documentation Group. [2230]
MySQL Native Driver (Mysqlnd)
plugin gets installed on the PHP application server, along with the
mysqlnd
plugins) can solve problems easily which otherwise would have required
mysqlnd
mysqlnd
plugin is bound to the request-based lifecycle of
libmysqlclient
plugin is implemented using the C API, any
mysqlnd
2546
plugin can be
mysqlnd
client and Connector/