Does recycling the IIS7 application pool kill any currently executing requests? Or does it wait for all requests to complete (like a drain-stop)?
I don't want the recycling rules to cause intermittent errors from my WCF sites.
Thanks
No.
By default, the WWW service
establishes an overlapped recycle, in
which the worker process that is to be
terminated is kept running until after
a new worker process is started.
This is from the Documentation for IIS6 and I am sure it applies for IIS7.
If your web service requests are long-running, you might consider increasing the shutdown timeout.
Yes. Recycling an application pool causes the WWW service to shut down all running worker processes that are serving the application pool, and then start new worker processes.
This is from the Documentation for IIS6 and I am sure it applies for IIS7
Related
We have an application pool dedicated to a WCF service that is called infrequently (maybe 15-20 times per day). The calls can take several minutes, however, and the other day we got burned when IIS recycled the app pool while the call was still processing because the shutdown timeout ran out.
We're considering using request limit recycling, instead, but my question is this: When the application pool recycles "after x requests", is that after the xth request completes? Or does it kick off the request, start the overlapped process to handle new requests, then subject the xth request to the same shutdown timeout that currently burns us?
Question in a similar vein:
How to detect if the current application pool is winding up in IIS7.5 and Asp.Net 3.5+
Check your Shutdown Time Limit setting on the app pool.
Regardless of how you do the recycling, this setting is checked to determine how long a request is allowed to carry on for before being forcibly shut down.
When an app pool is recycled, IIS attempts to drain the running requests from the app pool first, and then a in the meantime a new app pool is already started which accepts new requests. By making the setting high enough to accommodate your long running requests, you will allow IIS to safely drain the old app pool.
I recommend you do the following.
1- Create a bool Ping() { return true;} method under your WCF service.
2- Create an IIS web application responsible of polling the Ping() method. This is the only way i found to keep my WCF services alive.
3- WCF long running operations must be called also from another background IIS process (web app) that must read from a message queue and call the WCF operation. So you need to log the WCF long running operation call requests in queues. This way, you will have the possibility of retrying the call if the app pool where your WCF services are hosted shuts down.
While deploying changes to WCF Service, the app-pool is stopped. Hosted on IIS8. Messages are queued by MSMQ, however we are concerned that in-process services will fail when the app-pool is stopped. Does anyone know if the app pool is stop is smart enough to allow current processes to finish prior to shutting down?
I have to implement long running process which is starts via request to the wcf method (not start proces when application start)
I now that this is wrong solution, better will be windows serwis or something else for long running process, but for my situation it is impossible. I have to use wcf servis hosted on IIS.
I read about appdomain recycled and I can't figure out thing about Idle Timeout - appdomain restart if request run over 20 minutes. I know that this issue appears when is started background task in application start.
So will be my appdomain kill when (idle timeout is setup 20 minutes).
it is start one long running request, and after that will be not another request.
When process is started in application start IIS nothing knows about this task and this is for me clear that in this situation appdomain is closed
Does after 20 minutes IIS kill appdomain, besides that eier request still running ? I am confused, because IIS know about still running request and mayby does not do this.
What is true ?
Yes, IIS will kill the process because it works on a rolling horizon of requests, not what is running. A way around this might be to have the web service request itself while it is running to continually ping the server to let it know that it is still running. But on the whole, IIS will kill its processes when no requests are coming in.
Taken directly from MSDN: The worker process shuts down after it finishes processing its existing requests, or after a configured time-out, whichever comes first.
In your case, if your process is longer than the timeout, your process will never finish.
I have a WCF Service hosted in IIS 7.5 that is responding to the first soap message posted to it after inactivity with a 404 Error.(It works around 15 seconds after that...it is likely waking up after that initial ping.)
In investigating this issue I have:
-Prevented App Pool Recycling by setting the Idle Time-out to 0 and the recycling time interval to 0
- Attempted to enable the app warmer by installing Microsoft's App Inititializer and
amehrots app initializer ui for iis 7.5. Using this I set the application pool to always running and preloaded/preinitted my service.
- Installed http://keepalive.codeplex.com/ to run through the metabase and hit the service with activity.
While the service is active following an iis restart, it still appears to sleep after a period of inactivity. I am currently looking into reliable sessions and whether tweaks can be made to the web.config. Any further guidance would be appreciated.
There is an idle time setting on the Application pool.
The default is 20 mins, if there is no Activity for 20 mins the app pool is released from memory. The first Call after that will trigger a load and JIT compile of the code.
You can stop the shutdown by setting the idle time to 0.
I decided to give up on my attempts at an elegant solution and ended up adding a windows service to send a web request to each of the urls that I needed to keep alive.
I have a WCF service running under a service user on my local system. Every time I try to debug it is giving me a message Attach Security warning.
In Visual Studio, by default (even without attaching), I get this error:
Attaching to this process can potentially harm your computer. If the
information below looks suspicious or you are unsure, do not attach to
this process
Name: C:\Windows\System32\inetsrv\w3wp.exe
What is w3wp.exe? According to a Google search, I think it is related to IIS. But what does it do? What setting should be changed so that this won't give this message everytime I try to debug on my local system?
An Internet Information Services (IIS) worker process is a windows
process (w3wp.exe) which runs Web applications, and is responsible for
handling requests sent to a Web Server for a specific application
pool.
It is the worker process for IIS. Each application pool creates at least one instance of w3wp.exe and that is what actually processes requests in your application. It is not dangerous to attach to this, that is just a standard windows message.
Chris pretty much sums up what w3wp is. In order to disable the warning, go to this registry key:
HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\10.0\Debugger
And set the value DisableAttachSecurityWarning to 1.
A worker process runs as an executables file named W3wp.exe
A Worker Process is user mode code whose role is to process requests,
such as processing requests to return a static page.
The worker process is controlled by the www service.
worker processes also run application code, Such as ASP .NET
applications and XML web Services.
When Application pool receive the request, it simply pass the request
to worker process (w3wp.exe) . The worker process“w3wp.exe” looks up
the URL of the request in order to load the correct ISAPI extension.
ISAPI extensions are the IIS way to handle requests for different
resources. Once ASP.NET is installed, it installs its own ISAPI
extension (aspnet_isapi.dll)and adds the mapping into IIS.
When Worker process loads the aspnet_isapi.dll, it start an
HTTPRuntime, which is the entry point of an application. HTTPRuntime
is a class which calls the ProcessRequest method to start Processing.
For more detail refer URL
http://aspnetnova.blogspot.in/2011/12/how-iis-process-for-aspnet-requests.html
w3wp.exe is a process associated with the application pool in IIS. If you have more than one application pool, you will have more than one instance of w3wp.exe running. This process usually allocates large amounts of resources. It is important for the stable and secure running of your computer and should not be terminated.
You can get more information on w3wp.exe here
http://www.processlibrary.com/en/directory/files/w3wp/25761/