ConFoo 2025

    Memcache::connect

    (PECL memcache >= 0.2.0)

    Memcache::connect — Open memcached server connection

    Description

    Memcache::connect(string $host, int $port = ?, int $timeout = ?): bool

    Memcache::connect() establishes a connection to the memcached server. The connection, which was opened using Memcache::connect() will be automatically closed at the end of script execution. Also you can close it with Memcache::close(). Also you can use memcache_connect() function.

    Parameters

    host

    Point to the host where memcached is listening for connections. This parameter may also specify other transports like unix:///path/to/memcached.sock to use UNIX domain sockets, in this case port must also be set to 0.

    port

    Point to the port where memcached is listening for connections. Set this parameter to 0 when using UNIX domain sockets.

    Please note: port defaults to memcache.default_port if not specified. For this reason it is wise to specify the port explicitly in this method call.

    timeout

    Value in seconds which will be used for connecting to the daemon. Think twice before changing the default value of 1 second - you can lose all the advantages of caching if your connection is too slow.

    Return Values

    Returns true on success or false on failure.

    Examples

    Example #1 Memcache::connect() example

    <?php

    /* procedural API */

    $memcache_obj = memcache_connect('memcache_host', 11211);

    /* OO API */

    $memcache = new Memcache;
    $memcache->connect('memcache_host', 11211);

    ?>

    Notes

    Warning

    When the port is unspecified, this method defaults to the value set of the PHP ini directive memcache.default_port If this value was changed elsewhere in your application it might lead to unexpected results: for this reason it is wise to always specify the port explicitly in this method call.

    See Also

    Found A Problem?

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
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    User Contributed Notes 2 notes

    up
    10
    geoffrey dot hoffman at gmail dot com
    14 years ago
    If memcached is working, calling memcache_connect( ) returns an Object instance, not a boolean. If memcached is not working, calling memcache_connect( ) throws a notice AND a warning (and returns false as expected).

    <?php
    /* memcache is running */
    $test1 = memcache_connect('127.0.0.1',11211);
    echo     gettype($test1);
    // object
    echo get_class($test1);
    // Memcache

    /* memcached is stopped */
    $test2 = memcache_connect('127.0.0.1',11211);

    /*
    Notice: memcache_connect(): Server 127.0.0.1 (tcp 11211) failed with: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
    (10060) in C:\Program Files\Support Tools\- on line 1

    Warning: memcache_connect(): Can't connect to 127.0.0.1:11211, A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
    (10060) in C:\Program Files\Support Tools\- on line 1
    */

    echo gettype($test2);
    // boolean
    echo $test2===false;
    // 1
    ?>

    There appears to be no way to check whether memcached is actually running without resorting to error suppression:

    <?php
    $test3     = @memcache_connect('127.0.0.1',11211);
    if(     $test3===false ){
    // memcached is _probably_ not running
    }
    ?>
    up
    -4
    webysther at gmail dot com
    10 years ago
    In describing the timeout there is a statement that is not completely correct, increase the timeout does not necessarily preclude or unfeasible memcache, only allows the system to wait for more concurrent connections, which is a large minority of the number of connections, this causes several problems and could simply be corrected if the timeout was increased and perform some tests.
    To prove the concept and show that the connection does not wait if the server goes down:

    <?PHP

    while ( ++$loop < 10000 ) {
    try {
    $memcache = new Memcache;
    @    $memcache->pconnect( "127.0.0.1" , 11211 , 30 );
    $loopset = 0;
    $loopget = 0;

    while ( ++    $loopset < 50 ) {
    if ( @    $memcache->set( "foo" , "bar" ) === false ) {
    echo     "Fail!" . PHP_EOL;
    }
    }

    while ( ++    $loopget < 500 ) {
    if ( @    $memcache->get( "foo" ) === false ) {
    echo     "Fail!" . PHP_EOL;
    }
    }

    if (     $loop % 100 == 0 ) {
    echo     "Try: " . $loop . PHP_EOL;
    }
    } catch (     Exception $e ) {
    echo     "Fail: " . $e->getMessage() . PHP_EOL;
    }
    }

    ?>

    Replace with an invalid host and test the timeout will not make a difference! It serves only for connections to the socket that are occupied.

    More detail about troubleshooting timeouts in memcached google code.
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