• Concepts
  • Connection pool

  • Connection pool
  • Connection pool

    Connection pool

    The plugins connection pool is created when PHP
    initializes its modules (MINIT) and free’d when PHP shuts
    down the modules (MSHUTDOWN). This is the same as for
    persistent MySQL connections.

    Depending on the deployment model, the pool is used
    for the duration of one or multiple web requests. Network
    connections are bound to the lifespan of an operating system level
    process. If the PHP process serves multiple web requests as it is
    the case for Fast-CGI or threaded web server deployments, then the
    pooled connections can be reused over multiple connections. Because
    multiplexing means sharing connections, it can even happen with a
    threaded deployment that two threads or two distinct web requests
    are linked to one pooled network connections.

    A pooled connection is explicitly closed once the
    last reference to it is released. An implicit close happens when
    PHP shuts down its modules.