Re: undetected closed apps

[Jamal Hadi Salim <jhs@mojatatu.com>]

On 12/14/13 15:06, Michael Tuexen wrote:
> On Dec 14, 2013, at 8:09 PM, Jamal Hadi Salim <jhs@mojatatu.com> 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