Predis - Catch connection error

Question

Hi I have the following:

// Named array of connection parameters:
    $redis = new Predis\Client([
        'scheme' => 'tcp',
        'host'   => $host,
        'port'   => $port,
        'password'   => $auth,
    ]);

    try {
        // explicitly call Predis\Client::connect()
        $redis->connect();
    }
    catch (Exception $e) {
        return Redirect::to('profile')
                ->with('result', '<div class="col-lg-12"><div class="alert alert-danger alert-border-left alert-gradient alert-dismissable">
                <button aria-hidden="true" data-dismiss="alert" class="close" type="button">×</button>
                <i class="fa fa-check pr10"></i>
                <strong>Error - '.$e.'</strong> Unable to connect to redis server, please double check your database detals.</div></div>');
    }

However this isn't catching errors such as NOAUTH.

Can someone point me in the correct direction?

Answer 1

I read extensively about this issue, and although my configuration is different since it is using multiple servers, and the problem I was trying to solve was a failed server, this seems to have done it for me:

 try {
      $client = new Predis\Client($params);
      $client->connect();
 } catch(Predis\Connection\ConnectionException $e) {
      echo $e->getMessage();
 }

I tried many variations and this seems to stop all the screaming from the application. In my case I passed in an array of servers and attempt to ping them and remove the server which fails. It seems like overkill but how else will I know if the server is down without doing that?

Also, if you do not attempt a connection then it will fail somewhere else, that is, the connection is lazy and will be called when it is actually needed--for me this always resulted in a connection error. Calling it myself before using it allowed me to catch the exception. Then I had to find out why Exception would not do and had to switch it to Predis\Connection\ConnectionException. It was way harder than it should have been.