Can you explain socket.timeout.ms ?

[ahordez]

I have some troubles to understand and configure a correct value for the conf variable "socket.timeout.ms" for my producers.

Important note : my producer are synchronous (it's a design requirement), so i do something like (sorry it's PHP :)).

function produce($message) {

    [...]
    $topic->produce(RD_KAFKA_PARTITION_UA, 0, $message, $key);
    $producer->flush(5000); //flush timeout is 5000ms
    [...]
    return;
}

I want a total maximum timeout of 5 seconds (5000ms) for this synchronous write in Kafka.

The documentation say "Default timeout for network requests. Producer: ProduceRequests will use the lesser value of socket.timeout.ms and remaining message.timeout.ms for the first message in the batch".

Is it ok to configure "socket.timeout.ms" like this ? :

$conf->set('socket.timeout.ms', 50);
$conf->set('message.timeout.ms', 4950); 

What is the exact mean of "timeout for network requests" in this context ? If a broker is busy or unavailable, does it mean that it will wait socket.timeout.ms (50ms in my example) and then retry again and again on all brokers until i reach 5000ms (or message correctly produced and flushed) ?

Or does it mean that my producer will permanently failed if it reach one time 50ms timeout on a network request ?