From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: Socket Server breaks after 1000 client requests Date: Thu, 31 Dec 2009 11:22:20 -0800 Message-ID: <4B3CF9EC.9070103@candelatech.com> References: <2d05c4580912311111w6abaa007y5d212dd8fbde24d9@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Dragoslav Zaric Return-path: Received: from mail.candelatech.com ([208.74.158.172]:53611 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752163AbZLaTWX (ORCPT ); Thu, 31 Dec 2009 14:22:23 -0500 In-Reply-To: <2d05c4580912311111w6abaa007y5d212dd8fbde24d9@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/31/2009 11:11 AM, Dragoslav Zaric wrote: > Hi, > > I wrote C++ Socket class. This class wraps methods both for client and server, > so you can create server or client depending what methods you call. > > Anyway, all in all, problem is: This is likely some bug with your code..as I have code that easily handles 10k connections. > I have 3 small programs. One is server that listens in loop on port 30000. > Second is client program that sends one message to the server. > The third one on is small program (called spawn) that forks and > executes client program in limited for loop. So , idea is to simulate > a lot of connections to the server and see how many he can handle and > how. Use non-blocking IO and poll() instead of forking for each client. 10k processes are going to take almost any machine to it's knees. > > So, at first I start server, execute spawn, and server gets client > messages. First I try 10 clients, then 100, then 1000 and it worked > Then I tried 10000 clients, and then it breaks just above 1000 > clients, plus minus 100 !! So then I tried to put in server code 5 > threads and mutex, but the result is same around 1000 clients and > breaks. Then I put semaphore, but then i realized that in this > scenario semaphores are of no use, because you can not sync with > random client events. > > I also tried to change value in listen() method, but then I read > somewhere that maximum is 5 connections, which is default. No, you can easily make this bigger, and default is 128 for somaxconn echo -n "Increase somaxcon to 10000......................................... " echo 10000 > /proc/sys/net/core/somaxconn echo "DONE" You should also let us know what you mean by 'it breaks'. What exactly breaks? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com