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

[Vilius Adamkavicius]

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>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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>> Mono-devel-list at lists.ximian.com
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>>
>>
>
>


-- 
Regards,
Vilius.
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