• Concepts
  • Architecture

  • Architecture
  • Architecture


    The mysqlnd connection multiplexing plugin is
    implemented as a PHP extension. It is written in C and operates
    under the hood of PHP. During the startup of the PHP interpreter,
    in the module initialization phase of the PHP engine, it gets
    registered as a mysqlnd plugin to replace specific mysqlnd C

    The mysqlnd library uses PHP streams to communicate
    with the MySQL server. PHP streams are accessed by the mysqlnd
    library through its net module. The mysqlnd connection multiplexing
    plugin proxies methods of the mysqlnd library net module to control
    opening and closing of network streams.

    Upon opening a user connection to MySQL using the
    appropriate connection functions of either mysqli, PDO_MYSQL or ext/mysql, the plugin will
    search its connection pool for an open network connection. If the
    pool contains a network connection to the host specified by the
    connect function using the transport method requested (TCP/IP, Unix
    domain socket, Windows named pipe), the pooled connection is linked
    to the user handle. Otherwise, a new network connection is opened,
    put into the poolm and associated with the user connection handle.
    This way, multiple user handles can be linked to the same network