[Mono-dev] Self Hosted web service unstable – we see a new active port connection for each call

[Atsushi Eno]

Hi Vilius,

There isn't. As I wrote, there's a lot to do before that.

Atsushi Eno

On 2010/05/10 18:00, Vilius Adamkavicius wrote:
> Hi Atsushi,
>
> Thanks for your reply.
>
> Let me just ask if there is a schedule for further development on this 
> section?
>
> Regards,
> Vilius.
>
> On 10 May 2010 05:58, Atsushi Eno 
> <atsushieno at veritas-vos-liberabit.com 
> <mailto:atsushieno at veritas-vos-liberabit.com>> wrote:
>
>     Hello,
>
>     I will first stabilize existing stuff as well as fill missing
>     functionalities, and there is a lot to do. There isn't any kind of
>     optimization. I'd rather welcome your contributions and won't work
>     on it so far.
>
>     Atsushi Eno
>
>
>
>     On 2010/05/08 0:14, Vilius Adamkavicius wrote:
>
>
>         We have implemented a simple self hosted web service in .NET
>         using ServiceHost. The Client is a simple Silverlight app that
>         polls for updated info every 5 seconds. The return messages
>         tend to be no more that 1-10K.
>
>         We ported the web service (self-hosted) to MONO 2.6. This
>         seemed to go perfectly and it stood up to stress testing in
>         devel...then we deployed it. Now we find that the service is
>         unstable and can just hangs after anywhere between 2 minutes
>         and 2 days.
>
>         IP traces show that when it hangs the XML Post gets (request)
>         gets received by the webservice but nothing is ever
>         transmitted back. Also when it hangs netstat shows a
>         persistent active connection on the port to which it is allocated.
>
>         In an attempt to diagnose this we looked at the port behaviour
>         using netstat. We looked at this while the MONO implementation
>         of the webservice was running without problem; we compare this
>         to the active port connection behaviour of the windows/.NET
>         implementation- what found was worrying.
>
>         When we run a single client and connect the windows/.NET
>         version of the webservice we see *one port connection that
>         persists*.
>
>         When we run a single client and connect the MONO version of
>         the webservice we see it holds around *12-16 active port
>         connections at any one time*...and these seem to be
>         continuously dying and regenerating.
>
>         We postulated that each call to the webservice was making a
>         new connection (unlike Windows); each connection would be used
>         once and then timeout. Given the rate that the client polls we
>         estimated that the timeout must be around a minute...then we
>         found this in the MONO DefaultCommunicationTimeouts.cs
>
>         Vilius: private DefaultCommunicationTimeouts ()
>         {
>         close = open = send = TimeSpan.FromMinutes (1);
>         receive = TimeSpan.FromMinutes (10);
>         }
>
>         This strongly supports our theory...
>
>         The question is why does it keep creating a new connection for
>         each call? Can the MONO 2.6 implementation of ServiceHost
>         maintain a single connection for an application session (like
>         Windows .NET) ? What is the ramification of this?
>
>
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>
>
>
>
>
> -- 
> Regards,
> Vilius.