Request Current

  • Thread starter Thread starter Johan Karlsson
  • Start date Start date
J

Johan Karlsson

Hi!

I've have an asp.net application that calls a backend service hosted in IIS
using WCF. I'm having some performance issues that seems to be related to
hitting the maximum number of connections.

My initial question is:

The Request Current counter in ASP.NET never drops to zero. It gets stuck at
a minimum of 1-4. When the counter goes up to about 19-20 the application
locks. It looks like its the backend service that locks up since other
applications get a timeout calling other methods.

Should the Request Current counter drop to zero or is it normal that it
stays at 1-4?

Thanks
// Johan
 
Johan Karlsson said:
Hi!

I've have an asp.net application that calls a backend service hosted in IIS
using WCF. I'm having some performance issues that seems to be related to
hitting the maximum number of connections.
Click to expand...

The max number of concurrent connection to a WCF Web service is 5.
My initial question is:

The Request Current counter in ASP.NET never drops to zero. It gets stuck at
a minimum of 1-4. When the counter goes up to about 19-20 the application
locks. It looks like its the backend service that locks up since other
applications get a timeout calling other methods.
Click to expand...

Maybe, the WCF service aborted and the WCF client is not closing the
connection due to the abort, which is leaving the connection open.
Should the Request Current counter drop to zero or is it normal that it
stays at 1-4?
Click to expand...

You have 5 concurrent connections that can be used at any given time with a
WCF Web service. If the connection is not being closed properly by the
client, then you'll if the 5 concurrent connections pretty fast.
 
Hi!

Thanks for you reply!

Is there a way to change the number of concurrent connections? Five seems
kinda limited for a large number of users.

It still don't explain the Request Current counter in ASP.NET. It can be as
high as 19 before the app freezes up.

// Johan
 
Hi Johan,
I've have an asp.net application that calls a backend service hosted in IIS
using WCF. I'm having some performance issues that seems to be related to
hitting the maximum number of connections.
Click to expand...
My initial question is:
Click to expand...
The Request Current counter in ASP.NET never drops to zero. It gets stuck at
a minimum of 1-4. When the counter goes up to about 19-20 the application
locks. It looks like its the backend service that locks up since other
applications get a timeout calling other methods.
Click to expand...
Should the Request Current counter drop to zero or is it normal that it
stays at 1-4?
Click to expand...

You may set some WCF serviceThrottling settings to see whether it works:

http://msdn.microsoft.com/en-us/library/ms731379.aspx

As to the Request Current counter it's normal that it's not zero however
since you said the application locks definitely something is wrong.

Please let me know whether the serviceThrottling can resolve this issue.

Regards,
Allen Chen
Microsoft Online Support

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Hi Johan,
I've have an asp.net application that calls a backend service hosted in IIS
using WCF. I'm having some performance issues that seems to be related to
hitting the maximum number of connections.
Click to expand...
My initial question is:
Click to expand...
The Request Current counter in ASP.NET never drops to zero. It gets stuck at
a minimum of 1-4. When the counter goes up to about 19-20 the application
locks. It looks like its the backend service that locks up since other
applications get a timeout calling other methods.
Click to expand...
Should the Request Current counter drop to zero or is it normal that it
stays at 1-4?
Click to expand...

Do you have any progress on this issue?

Regards,
Allen Chen
Microsoft Online Support
 
Hi!

I'm sorry for the delay of the answer, I've been on a four day vacation in a
cabin without electricity.

I tried the following settings and it seems to mitigate the issue. What
settings are recommended?

<serviceThrottling maxConcurrentCalls="100" maxConcurrentSessions="100"/>

The call to the service is through a session-enabled webservice to keep the
calling user authenticated. I also lowered the rate of calls to the
webservice.

Thanks

/Johan
 
Hi Johan,
I tried the following settings and it seems to mitigate the issue. What
settings are recommended?
Click to expand...
<serviceThrottling maxConcurrentCalls="100" maxConcurrentSessions="100"/>
Click to expand...

The answer is it depends. If your server is very powerful you can set it a
bit larger. These settings are used to prevent server from resource
exhaustion. My suggestion is to do some load tests to decide what value to
set in your scenario.

Please feel free to ask if you have additional questions.

Regards,
Allen Chen
Microsoft Online Support

Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
(e-mail address removed).
 
Hi!

I'll do that. What seems weird is that the calls take longer than expected
and there is no locking in the database?

// Johan
 
Hi Johan,
I'll do that. What seems weird is that the calls take longer than expected
and there is no locking in the database?
Click to expand...
// Johan
Click to expand...

From your description you call database in your web service, which takes
quite long time right? You may test the same logic in a Console application
to see whether you get the same behavior. Some load tests for database
would also be helpful to isolate the problem. If finally it turns out to be
a database issue and you're using SQL Server I recommend you ask question
in http://technet.microsoft.com/en-us/sqlserver/bb895986.aspx

Regards,
Allen Chen
Microsoft Online Support

Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
(e-mail address removed)
 
Hi Johan,

Do you have any progress on this issue?

Regards,
Allen Chen
Microsoft Online Support

Delighting our customers is our #1 priority. We welcome your comments and
suggestions about how we can improve the support we provide to you. Please
feel free to let my manager know what you think of the level of service
provided. You can send feedback directly to my manager at:
(e-mail address removed)
 
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