Application Pool Limits

Hi,

I have a web server that hosts more than 200 websites and has about 200
Applications under Default Application Pool.
Since last few weeks I have noticed that the Default Application Pool is not
terminating properly during Worker process recycling events (after certain
time).
I can see messages like:
"A process serving application pool 'DefaultAppPool' exceeded time limits
during shut down. The process id was '3236'." in the event log, right before
the IIS stops responding.

What might be causing the problem ?
* Over loaded DefaultAppPool ( about 200 Apps)
* Buggy Code in Applications (causing memory leaks ?? )

Thanks in advance :)

Re: Application Pool Limits

On Nov 15, 6:58 am, "spitfire" wrote:
> Hi,
>
> I have a web server that hosts more than 200 websites and has about 200
> Applications under Default Application Pool.
> Since last few weeks I have noticed that the Default Application Pool is not
> terminating properly during Worker process recycling events (after certain
> time).
> I can see messages like:
> "A process serving application pool 'DefaultAppPool' exceeded time limits
> during shut down. The process id was '3236'." in the event log, right before
> the IIS stops responding.
>
> What might be causing the problem ?
> * Over loaded DefaultAppPool ( about 200 Apps)
> * Buggy Code in Applications (causing memory leaks ?? )
>
> Thanks in advance :)


It's either a bug in the applications running in Default Application
Pool, or perhaps your application rightfully takes a long time to
shutdown and IIS's timer needs to be increased. You have to determine
which is th e case.


//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David.Wang
//

Re: Application Pool Limits

"David Wang" wrote in message
news:33e87d33-d165-4814-a801-4706dce0b92f@s6g2000prc.googleg roups.com...
> On Nov 15, 6:58 am, "spitfire" wrote:
>> Hi,
>>
>> I have a web server that hosts more than 200 websites and has about 200
>> Applications under Default Application Pool.
>> Since last few weeks I have noticed that the Default Application Pool is
>> not
>> terminating properly during Worker process recycling events (after
>> certain
>> time).
>> I can see messages like:
>> "A process serving application pool 'DefaultAppPool' exceeded time limits
>> during shut down. The process id was '3236'." in the event log, right
>> before
>> the IIS stops responding.
>>
>> What might be causing the problem ?
>> * Over loaded DefaultAppPool ( about 200 Apps)
>> * Buggy Code in Applications (causing memory leaks ?? )
>>
>> Thanks in advance :)
>
>
> It's either a bug in the applications running in Default Application
> Pool, or perhaps your application rightfully takes a long time to
> shutdown and IIS's timer needs to be increased. You have to determine
> which is th e case.
>
>
> //David
> http://w3-4u.blogspot.com
> http://blogs.msdn.com/David.Wang
> //

Thanks David.
I noticed that it takes about 10-12 minutes for the w3wp process to
shutdown. Is this normal ?? I have increased shutdown time limit though.
I was running process monitor and I noticed that the w3wp process was still
creating new threads even after I Recycled DefaultAppPool.
Finally it ended after 12 minutes.

Re: Application Pool Limits

On Nov 16, 7:40 am, "spitfire" wrote:
> "David Wang" wrote in message
>
> news:33e87d33-d165-4814-a801-4706dce0b92f@s6g2000prc.googleg roups.com...
>
>
>
>
>
> > On Nov 15, 6:58 am, "spitfire" wrote:
> >> Hi,
>
> >> I have a web server that hosts more than 200 websites and has about 200
> >> Applications under Default Application Pool.
> >> Since last few weeks I have noticed that the Default Application Pool is
> >> not
> >> terminating properly during Worker process recycling events (after
> >> certain
> >> time).
> >> I can see messages like:
> >> "A process serving application pool 'DefaultAppPool' exceeded time limits
> >> during shut down. The process id was '3236'." in the event log, right
> >> before
> >> the IIS stops responding.
>
> >> What might be causing the problem ?
> >> * Over loaded DefaultAppPool ( about 200 Apps)
> >> * Buggy Code in Applications (causing memory leaks ?? )
>
> >> Thanks in advance :)
>
> > It's either a bug in the applications running in Default Application
> > Pool, or perhaps your application rightfully takes a long time to
> > shutdown and IIS's timer needs to be increased. You have to determine
> > which is th e case.
>
> > //David
> >http://w3-4u.blogspot.com
> >http://blogs.msdn.com/David.Wang
> > //
>
> Thanks David.
> I noticed that it takes about 10-12 minutes for the w3wp process to
> shutdown. Is this normal ?? I have increased shutdown time limit though.
> I was running process monitor and I noticed that the w3wp process was still
> creating new threads even after I Recycled DefaultAppPool.
> Finally it ended after 12 minutes.- Hide quoted text -
>
> - Show quoted text -


Default Shutdown time limit is something like 90 seconds, and most
good applications shutdown within 1-2 seconds.

I cannot tell you whether 10-12 minutes is "normal" or not for your
applications. My feeling is that it is abnormal.

However, you should NOT increase shutdown time limit simply to "avoid"
the event log message because it merely robs you of an IIS6 Health
Monitoring feature. If you change the time limit so large as to be
meaningless, then IIS6 might as well not monitor your applications'
health nor the application's impacts on server performance. If that is
your intent, then certainly feel free to disable IIS6's Health
monitoring metrics.

Depending on your actual Application Pool configuration, the behavior
of not immediately terminating the worker process is possible. For
example, if the shutdown time limit is 90 seconds, then IIS will wait
for 90 seconds, after process cycle is initiated, before terminating
any long-running activity inside that process (unless other flags are
enabled). Suppose you had an application that took 12 minutes to
shutdown. IIS will wait 90 seconds after recycling is triggered
manually or via some other health monitoring metric, and then
terminate that web application's process and report the event log
entry.

If you changed the timeout to be 15 minutes and then initiated
recycle, then IIS can let the worker process run for 12 minutes,
creating threads, etc. In that case, IIS will wait for up to 15
minutes and in the 12th minute, the application shuts itself down, so
IIS will not report any event log entry for timeout during shutdown
and wait the

In other words, I understand your concern that recycling an
application pool does not seem to immediately terminate the worker
process, but please understand that recycling never meant "immediately
terminate". It means "gracefully wait for X amount of time to allow
graceful shutdown by unknown applications BEFORE forciably taking
action".


//David
http://w3-4u.blogspot.com
http://blogs.msdn.com/David.Wang
//