From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Date: Sun, 15 Dec 2013 15:21:40 +0000 Subject: Re: undetected closed apps Message-Id: <52ADC904.7010100@mojatatu.com> List-Id: References: <52AC7375.6010505@mojatatu.com> In-Reply-To: <52AC7375.6010505@mojatatu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sctp@vger.kernel.org On 12/14/13 15:06, Michael Tuexen wrote: > On Dec 14, 2013, at 8:09 PM, Jamal Hadi Salim wrote: > In FreeBSD it can be controlled by a sysctl: > net.inet.sctp.shutdown_guard_time: 180 > Don't know about Linux. The kernel seems to have it - but i cant see any knob exposed to user space. Can someone from the Linux world point me to some stats i can collect in user space that will narrow this down? There has to be something. I dont have the luxury of doing git bisect (rephrase: These kernels are deployed, upgrade is almost a no option). >> Waiting for a few hours last time didnt seem to cure this. > OK. > > But the suggested value is 3 Minutes... > Understood - but i thought if i waited longer than 3 minutes then that would cover it, no? I tried a few other things from the server side to detect if the client is gone: - peek read (claimed all was good) - getsockopt some random value (claimed all was good) All understandable given the socket state seems to be still intact. So the only option that still seem left for me is to implement app level heartbeats to detect dead clients. cheers, jamal