MySQL PDO Cannot assign requested address

Can someone help me with this error?

[08-Apr-2013 17:44:08 Europe/Berlin] PHP Warning:  PDO::__construct(): [2002]
    Cannot assign requested address (trying to connect via tcp://****:3306) in 
    /var/www/***
[08-Apr-2013 17:44:08 Europe/Berlin] PHP Fatal error:  Uncaught exception 
    'PDOException' with message 'SQLSTATE[HY000] [2002] Cannot assign requested 
    address' in /var/www/***

I have a Server with a lot connections per second; out of about 100 Connections, a single one got this error.

I've tried this recommendation from stackoverflow however it does not solve my problem.

Using a persistent connection worked for me. The linked recommondation above shows how to create a persistent connection with mysqli. I am using PDO, too. So I had to add the following to my connection-call:

$mysql = new PDO(
    "mysql:host=$mySqlServer;dbname=$mySqlDatabase;charset=utf8",
    $mySqlUser,
    $mySqlPassword,
    array(PDO::ATTR_PERSISTENT => true));

More information and possible limitations can be found here: http://php.net/manual/de/pdo.connections.php

StackExchange Database Administrators Q#39509, answer score: 3