From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M1AsK-0004z6-L2 for qemu-devel@nongnu.org; Mon, 04 May 2009 22:59:20 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M1AsG-0004yu-5h for qemu-devel@nongnu.org; Mon, 04 May 2009 22:59:20 -0400 Received: from [199.232.76.173] (port=33101 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M1AsF-0004yr-Vi for qemu-devel@nongnu.org; Mon, 04 May 2009 22:59:16 -0400 Received: from rv-out-0708.google.com ([209.85.198.246]:21136) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1M1AsF-0000XX-JR for qemu-devel@nongnu.org; Mon, 04 May 2009 22:59:15 -0400 Received: by rv-out-0708.google.com with SMTP id c5so2894882rvf.22 for ; Mon, 04 May 2009 19:59:13 -0700 (PDT) Message-ID: <49FFAB7D.4000304@gmail.com> Date: Mon, 04 May 2009 20:59:09 -0600 From: David Ahern MIME-Version: 1.0 Subject: Re: [Qemu-devel] PATCH: enabling TCP keepalives - v3 References: <49F9FEBA.6050901@gmail.com> <20090501113204.GA10763@amd.home.annexia.org> <49FAEFDD.2070002@gmail.com> <20090501152312.GH13308@redhat.com> <49FB1979.1070706@gmail.com> <20090505013158.GB12731@shareable.org> In-Reply-To: <20090505013158.GB12731@shareable.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jamie Lokier Cc: qemu-devel@nongnu.org, Paul Brook , "Richard W.M. Jones" Jamie Lokier wrote: >> The parameters I put in cause a drop after 2 minutes of no response -- >> 60 seconds of idle (no data through the socket) followed by 60 seconds >> of failed probes. The default parameters for linux are harsh: 7 hours of >> idle time before the first keepalive is sent. > > Is 7 hours a problem worth overriding the kernel defaults for? How > many old VNC sessions are likely to get accumulated in that time? The linux default is 7200 seconds; I'm not sure how I manage to convert 7200 seconds to 7 hours. > > 2 minutes is a bit fast for a truly idle session, but as I said in > another response, if you have data sent by either end, then the > session will be broken by the lack of response in about 2 minutes > anyway - without keepalives. Version 5 of the patch drops the changes to the timers and the missed probes count; it only enables tcp keepalives and the probes are sent based on OS defaults. david > > -- Jamie