Re: undetected closed apps

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

More info:

1) In the non-working case I dont see the shutdown sequence on tcpdump
2) Thing seem to break only when i have a number of SEND_FAILED events
when i read. The brain in my stomach is thinking this probably has to
do with some outstanding obsoleted messages which the app didnt have
a chance to do recv on although cat /proc/net/sctp/assocs shows
both send/recv queue at 0.

cheers,
jamal

On 12/14/13 10:16, Jamal Hadi Salim wrote:
>
> I wasnt clear, sorry. Basically I kill the app after it sends
> a 100K or more messages (about 300 bytes each). The server
> is still thinking the client is connected. The client does
> a close/shutdown. I enabled SCTP heartbeats between the client
> and server and running tcpdump after killing the client
> shows heartbeats going on happily.
>
> Sorry - I cant put out out the code, it is too big to cut
> down into something small enough to demonstrate.
>
> cheers,
> jamal
>
>
> On 12/14/13 10:04, Jamal Hadi Salim wrote:
>>
>> Folks,
>>
>> I have a problem which manifests in kernels > 3.8. I am no sure how
>> best to debug it.
>> I have looked at strace and dont see anything different between when it
>> works (kernels <= 3.8) and when it doesnt (kernels > 3.8).
>> When i dump /proc/net/sctp/assocs I can see in the non-working case
>> the socket is still there - which means there is no way for the server
>> to be notified.
>> If kill the server, the socket disappears.
>>
>> Is there something else that would help narrow this down?
>>
>> cheers,
>> jamal
>>
>> PS:
>> Essentially I have a client app that does some nasty stuff (on purpose
>> to test robustness). Client and server are connected locally within same
>> machine.
>> Client sends as fast as it can packets with partial reliability (timeout
>> of about 100ms). The only time client checks for any kernel obsoleted
>> msgs is when the send socket queue write will block.
>