I have 70 000 URLs (almost all on different servers) to check every day and I have to check them as quickly as possible (max 60 min). Depending on sever on witch document is located it take from 1 to 4 seconds to make head request. So, if I want make 70 000 / 60 / 60 = 20 requests per second, I need at least 50 threads working parallel. CPU load isn’t very high because almost all the time thread is waiting for response from the server.

I’ll rewrite code a bit.
sub thread_do
{
    # while not all urls are checked
    while (!$DONE) {
        # get new url from boss thread
        my $url = $task_q->dequeue();
        # check url
        my $ua = LWP::UserAgent->new(timeout => 3);
        my $res = $ua->request(HEAD $url);
        # return result to the boss thread
        $result_q->enqueue(
            "$tid;$url;" 
            . $res->code() 
            . ";" 
            . $res->message() 
            . ";"
        );
    }

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$DONE is a shared variable and the boss thread set it true when all urls are checked.

I used prethreading that means that I create number of threads and each thread process the same task number of times. In my example each thread makes head request until all urls are checked.

In reply to Re^5: Problem with ithreads by 2NetFly
in thread Problem with ithreads by 2NetFly

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