From owner-freebsd-net Tue Oct 9 13:55:46 2001 Delivered-To: freebsd-net@freebsd.org Received: from wren.cs.unc.edu (wren.cs.unc.edu [152.2.128.86]) by hub.freebsd.org (Postfix) with ESMTP id E83FC37B409 for ; Tue, 9 Oct 2001 13:55:39 -0700 (PDT) Received: from le-cs.cs.unc.edu (IDENT:le@le-cs.cs.unc.edu [152.2.131.150]) by wren.cs.unc.edu (8.9.3/8.9.3) with ESMTP id QAA22318 for ; Tue, 9 Oct 2001 16:55:36 -0400 (EDT) Date: Tue, 9 Oct 2001 16:55:36 -0400 (EDT) From: Nguyen-Tuong Long Le To: Subject: Connect(2) problem Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hi all, I have a software that simulates web clients and servers to create network congestion (for the purpose of doing research in network congestion). In our experiment, a client opens an HTTP connection to a server, fetches a number of objects, and then closes the connection. A problem I seem to have right now is that a client machine cannot simulate more than 3000 connections. When my client machine simulates more than 3000 connections, it's able to open a socket but then connect(2) fails with errno 35 (Resource temporarily unavailable). Another interesting notice is that the connect(2) system call blocks for a few miliseconds before it fails although fcntl(2) was used to make the socket non-blocking. The OS version I am using is FreeBSD 4.3-release. I used sysctl to bump up kern.maxfiles and kern.maxfilesperproc to 16384. I also bumped up kern.ipc.somaxconn to 8192 on the server side. I recompiled the kernel with option NMBCLUSTERS=65536 to increase the number of mbufs. I guess that CPU is not the bottleneck since I have the same problem regardless whether I use a 300 MHz or a 1 GHz machine. Does anyone have any suggestion what kind of resources my client machine runs out and how I can fix it? Thanks, Long P.S. Please kindly email your reply to me since I am not on the list. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message