Hello NetWallah,

First of all, thanks for your answer.

And about the "lot of data" I'm doing test with files of more or less 100k lines of log file.

Usually the server will handle maxium 3-4 lines per connection and then parse it and update a table in mysql and log it to a csv file but I want it to be stable and dont break if any server do a full update of 10k-20k lines of logs

I tried to delete the global declaration and declare it in the while(1) loop, but it still breaks with only 1 connection. If I try it with

The problem I think is related to the writing on the log file, because if I comment the line that open the report file in append mode and write the buffer it breaks.

Now I'm doing tests with 3 simultaneous clients sending 250k lines in loop to the server and it handles it perfectly if I dont write it to the file, only print the ouptut to the console

    while(my $buffer = <$client_socket>){
        ....
        open(my $fh, '>>', $output) or die "Could not open file '$outp
+ut' $!";
        print $fh $buffer;
    }
[download]

#!/usr/bin/perl

use strict;
use warnings;
use threads;

use IO::Socket;

my $host    = '127.0.0.1';
my $port    = '1337';
my $proto    = 'tcp';
my $debug    = 1;

my $output     = 'report.txt';

my @allowed_ips = ('127.0.0.1');

sub Main
{
    # flush after every write
    $| = 1;

    # Bind to listening address and port
    my $socket    = new IO::Socket::INET(
        LocalHost => $host,
        LocalPort => $port,
        Proto     => $proto,
        Listen    => 5,
        Reuse     => 1
    ) or die "ERROR > Could not open socket: ".$!."\n";

    print "INFO  > Waiting for client connections on tcp:[$host]:$port
+...\n";

    my @clients = ();

    while(1){
            # Waiting for new client connection
            my $client_socket = $socket->accept();

            # Push new client connection to it's own thread
            push (@clients, threads->create(\&clientHandler, $client_s
+ocket));
            foreach(@clients){
                if($_->is_joinable()) {
                    $_->join();
                }
            }
    }
    $socket->close();
    return 1;
}

sub clientHandler
{
    # Socket is passed to thread as first (and only) argument.
    my ($client_socket) = @_;

    # Create hash for user connection/session information and set init
+ial connection information.
    my %user            = ();
    $user{peer_address} = $client_socket->peerhost();
    $user{peer_port}    = $client_socket->peerport();

    unless (client_allowed($user{peer_address})){
        print $client_socket "Server > Connection denied.\n";
        print "WARN  > Connection from $user{peer_address}:$user{peer_
+port} denied by IP policy.\n";
        $client_socket->shutdown(2);
        $client_socket->close();
        threads->exit();
    }

    print "INFO  > Client ".$user{peer_address}.":".$user{peer_port}."
+ has been conected.\n";

    # Let client know that server is ready for commands.
    print $client_socket "Server > Welcome to raClus-Server $user{peer
+_address}\n$user{peer_address}> ";

    # Listen for commands while client socket remains open
    while(my $buffer = <$client_socket>){

        # Accept the command `PING` from client with optional argument
+s
        if($buffer =~ /^PING(\s|$)/i)        {
            print $client_socket "Server > Pong!\n";
        }

        # Accept the command `HELLO` from client with optional argumen
+ts
        if($buffer =~ /^HELLO(\s|$)/i){
            print $client_socket "Server > Hello!\n";
            print $client_socket "Server > Your IP:\t".$user{peer_addr
+ess}."\n";
            print $client_socket "Server > Your Port:\t".$user{peer_po
+rt}."\n";
        }

        # This will terminate the client connection to the server
        if($buffer =~ /^QUIT(\s|$)/i){
            # Print to client, and print to STDOUT then exit client co
+nnection & thread
            print $client_socket "Server > GOODBYE\n";
            print "INFO  > Client ".$user{peer_address}.":".$user{peer
+_port}." has been disconnected.\n";
            $client_socket->shutdown(2);
            threads->exit();
        }

        print "DEBUG > $buffer" if $debug;

        # Escribimos en fichero de texto
        #open(my $fh, '>>', $output) or die "Could not open file '$out
+put' $!";
        #print $fh $buffer;

        print $client_socket "$user{peer_address} > ";
    }
    print "INFO  > Client ".$user{peer_address}.":".$user{peer_port}."
+ has been disconnected.\n";

    # Client has exited so thread should exit too
    threads->exit();
}

sub client_allowed
{
    my $client_ip = shift;
    return grep { $_ eq $client_ip || $_ eq '0/0' || $_ eq '0.0.0.0/0'
+ } @allowed_ips;
}

# Start the Main loop
Main();
[download]

Then, the problem is with the output to the log file, can I make it asyncronous or save it in cache and write when it can?