From owner-freebsd-net Mon Apr 15 0: 8: 2 2002 Delivered-To: freebsd-net@freebsd.org Received: from spf1.hq.outblaze.com (202-77-223-26.outblaze.com [202.77.223.26]) by hub.freebsd.org (Postfix) with ESMTP id 8135537B405 for ; Mon, 15 Apr 2002 00:07:58 -0700 (PDT) Received: from yusufg.portal2.com (202-77-223-2.outblaze.com [202.77.223.2]) by spf1.hq.outblaze.com (Postfix) with SMTP id 5DE8C26B99 for ; Mon, 15 Apr 2002 07:07:06 +0000 (GMT) Received: (qmail 13935 invoked by uid 500); 15 Apr 2002 07:07:53 -0000 Date: Mon, 15 Apr 2002 15:07:53 +0800 From: Yusuf Goolamabbas To: freebsd-net@freebsd.org Subject: Re: What does FreeBSD do when listen queue is full ? Message-ID: <20020415070753.GA13864@outblaze.com> References: <20020415062451.13653.qmail@yusufg.portal2.com> <20020415074210.V3157-100000@patrocles.silby.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020415074210.V3157-100000@patrocles.silby.com> User-Agent: Mutt/1.3.28i 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 > > There used to be two listen queues; one for completed connections and one > for incomplete connections. (Complete referring to the TCP three-way > handshake completing.) The syncache replaces the incomplete connection > queue, meaning that the listen queue depth is no longer relevant there. What is the maximum size of the queue for completed connections ? Is there a sysctl setting for this > I just did a quick look over the code, and it appears that the complete > connection queue is still intact, and takes on 3/2*listen backlog as its > length. Therefore, if sendmail is deciding to not accept() all > connections ASAP, a backlog will build up, and RSTs will be sent to > incoming connections. This should be true under 4.4 or 4.5. > > The listen manpage looks to be pretty accurate in its description. What about the statement 'or,if the underlying protocol supports retransmission, the request may be ignored so that retries may succeed' What does 'underlying protocol' refer to then since you are saying that even with TCP which supports retransmission, the stack sends a RST when the listen queue is full Regards, Yusuf -- Yusuf Goolamabbas yusufg@outblaze.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message