Connection timed out

[TehesFR]

Hi guys,

I have a strange behaviour using predis with a php/symfony application.
Everytime the application tries to connect to redis, I got this in the logs:

stream_socket_client(): unable to connect to tcp://redis_ip_server:6379 (Connection timed out)

This is not a firewall or remote connection issue because, if I use telnet on the exact same "redis_ip_server" and port 6379, the connection is OK and I'm able to set and get keys... so basically the connection is timed out only when using predis.

After a couple of hours, I've finally fixed this issue by changing one line in predis/src/Connection/StreamConnection.php on line 127:

if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout, $flags)) {
        $this->onConnectionError(trim($errstr), $errno);
}

BY

if (!$resource = @stream_socket_client($address, $errno, $errstr, $flags)) {
        $this->onConnectionError(trim($errstr), $errno);
}

I don't really understand why I have to do this...
Is it an issue on your side or mine ? I hope maybe you can help me understand.
For information, I'm using the official redis docker container as my redis server (v3.2.4).

Thanks a lot.

[nrk]

First thing, your change is actually wrong as you are passing the value of $flags as a timeout for stream_socket_client(). That said, considered that $flags is set to 4 (if you are not using persistent connections, the only connection flag is STREAM_CLIENT_CONNECT) which is smaller than the default value of $timeout used by Predis for connections (5 seconds) this behaviour doesn't make sense to me. Have you tried increasing the timeout for connection attempts, let's say to 30 seconds, just to see if anything changes? You can do it by setting timeout=30 in the connection parameters passed to Predis.

[TehesFR]

@nrk thanks for your answer, I've made some tests:

It's working fine with:

if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout=30, $flags)) {
if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout=5, $flags)) {
if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout=1, $flags)) {

And I have the error with:

if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout=0, $flags)) {
if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout, $flags)) {

[nrk]

Now I still don't get how it is even possible that you get an error when you don't assign a custom value to timeout via connection parameters considering this line where $timeout it is set to 5 seconds when nothing is specified by the user...

[itbdw]

@TehesFR

I guess you set a error config, say set a empty timeout, and as a result $timeout become to 0;

You may debug the timeout value passed to the function. What do you think, @nrk

    protected function createStreamSocket(ParametersInterface $parameters, $address, $flags)
    {
        $timeout = (isset($parameters->timeout) ? (float) $parameters->timeout : 5.0);

       //debug here
       var_dump($timeout);

        if (!$resource = @stream_socket_client($address, $errno, $errstr, $timeout, $flags)) {

            $this->onConnectionError(trim($errstr), $errno);
        }

[nrk]

I'm closing this due to lack of feedback, feel free to re-open it if you have more details to share and are still interested in it.