Setting a connect timeout with PDO

问题

I'm using PDO to get data off a MySQL server. What I noticed is this: if the MySQL server is unavailable, it takes really (relatively) long for this code to return an exception:

try {
  $handle = new PDO($db_type . ':host='.$db_host.';dbname='.$db_name,$db_user,$db_pass);
  // Tried using PDO::setAttribute and PDO::ATTR_TIMEOUT here
} catch(PDOException $e) {
  echo $e->getMessage;
}

In case of MySQL it takes just over 2 minutes for the exception to occur (SQLSTATE[HY000] [2003] Can't connect to MySQL server on...) and 30 seconds on PostgreSQL (SQLSTATE[08006] [7] timeout expired).

I tried using PDO::setAttribute and PDO::ATTR_TIMEOUT but it's not working. Which I guess makes sense, since the problem occurs before this statement.

Is there a way to set a timeout for connecting to the DB? 2 minutes/30 seconds seems really long to me for PDO to realize there is nothing there.

I think I saw this being done somewhere, but can't find it again for the life of me.

回答1:

$DBH = new PDO(
    "mysql:host=$host;dbname=$dbname", 
    $username, 
    $password,
    array(
        PDO::ATTR_TIMEOUT => 5, // in seconds
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
    )
);

回答2:

I'm using the DBLIB driver for PDO - and that doesn't support the passing of options (throws a warning).

To get round this, you can edit the connection_timeout setting in the FreeTDS config file which is located at /etc/freetds/freetds.conf (on Ubuntu).

来源：https://stackoverflow.com/questions/21403082/setting-a-connect-timeout-with-pdo