I have a WCF Service Deployed on IIS. (BasicHTTPBinding with [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)])
I have built custom in-memory session management and Now I am facing a strange problem that is IIS 7 Restarts Automatically without even throwing any kind of warning or error not even in EventLog. This problem leads to destroy the all available sessions.
I discovered this issue after logging the Application_Start and Application_End methods using log for net and also i put the break point in application_start and it paused there in between test execution.
This happens rarely but i need to know why it happens and if it is normal and acceptable or not. if not then what may be the possible reasons of this.
Regards
Mubashar Ahmad
Could it be the app pool being re-cycled? IIS 6 has this set on by default to 1740 minutes. As for IIS 7 I guess you would have the same kind of setting? I know in IIS 6 this "event" is not logged as 'n error.
IIS recycles worker processes either when it detects an "unhealthy" process, or after certain operator-configurable limits are reached.
Among the limits are:
memory threshold
after a configured number of requests
elapsed time
time of day
more info
The Session timeout (which is separate to the app pool recycling) is set to 90 minutes by default, this is set at the application level. This also means anything being held in Session will be blown away at that time. You can set it via the properties of the virtual directory/application in IIS6, and via SessionState->Open Feature in IIS7 (when you have the application selected).
Also note that session timeout can be set via the web.config of an ASP.Net application, should your web services be hosted in one of those.
Related
I have ASP .Net core webapi deployed on IIS 7.5 (Windows 2008 R2). I have controllers as well as listener classes (which wait for a message to arrive on a RabbitMQ message) which perform the same functionality.
The problem is whenever webapi is deployed on IIS or has some idle time, the RabbitMQ messages don't get picked up. Only if I make a API call to the control does the application 'wake up' and picks up the message.
Tweaks I have tried:
In the application pool,
set 'Idle timeout' to 0 .
set the 'Disable Overlapped Recycled' to true.
set 'Disable recycling for configuration changes'.
I have no idea what is causing this. I need the application to pick up messages immediately and have no idle time. Could anyone please point me in the right direction?
As a complete workaround, you can keep your app alive by sending requests all the time. In my case, I don't even have access to changing IIS settings.
To send requests I use Availability feature in Application Insights -- it lets you create tests that send GET requests to your app as often as every 5 minutes. You can read more about it here.
I have a new .netcore web app deployed to a windows server 2008R2 IIS instance, and after the app has been idle for a while, it's slow upon first load, and then subsequent requests are super fast.
In previous versions of .net I changed the Idle Time-out property of the app pool in IIS to 0 to fix this issue. Is there a similar setting somewhere with .netcore, perhaps something I've missed I could add to the Startup.cs file?
How about setting up the Application Pool Idle time on IIS?
Also make sure the recycling settings are unchecked
Baring there being a legitimate fix as I am unfamiliar with .netcore; writing a route which returns an HTTP 200 or something as a heartbeat and then calling it from a scheduled task every X minutes(idle - 1) would prevent the application from ever idling and thus keep it from slowing down requests.
I'm using Simple Injector in my WCF service. While running it from VS2010 everything is fine. However, when I publish it to my server using IIS 7, after some time (20 min, counted) my WCF loses all registered assemblies, modules, classes in container.
I guess IIS recycles the WCF Service Application Pool and drops my container registrations.
Can anyone help me on this?
While there exists many legitimate cases of using self-hosting WCF services, however, approaching self-hosting just because of IIS recycling may be counter productive.
Hosting in IIS gives you a lot benefit during development and daily operations, and I am not going to repeat what benefits which you could easily find out in google search.
So when IIS receive the first request to your application, it will launch a worker process named "w3wp.exe" according the settings in the application pool associated with your web app. And by default IIS will shutdown in 20 minutes of idle time. Check the Advanced Settings of the application pool, you will find a lot settings for the life cycle. You won't get such flexibility and robustness through self-hosting out of the box.
So basically you could have a few options provided you decide to stay with IIS hosting.
Change the Idle Time-out to 24-hours or even a month.
Write a small program or use cUrl to ping your application every 10 minute.
Leave it as it is
If you want to keep states during operations, save them in disk, then load them during next launch triggered by a request.
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.
We observed the following behavior on one of the servers hosting a WCF service on IIS 6.0:
The IIS log shows a high value for time-taken (> 100000)
The HTTP status code is 200
sc-win32-status code shows a value of 64
I found out that sc-win32-status code of 64 indicates "The specified network is no longer available"
Initially I suspected that it could be because of limits set on MinFileBytesPerSecond, which sets the minimum throughput rate that HTTP.sys enforces when sending data from the client to the server, and back from the server to the client.
But the value for sc-bytes and cs-bytes indicate that the amount of data is sent is within the range generally observed for the service.
Also note that the WCF service is hosted on four boxes and is load-balanced, but the problem occurs only one of the servers. (but not essentially on the same server). The problem is also intermittent.
Has anybody else encountered this error? Any clues about what could be wrong?
Update
Note: Observation on IIS 7.5 (IIS version does not really matter)
I was able to replicate the issue. The issue occurs if:
1. The WCF service takes a long time to respond
2. The client proxy times out before it receives a response from the server. In this case it leads to TimeoutException on the client.
3. The server keeps waiting for TCP ACK for the client, which it would never receive.
Hence a long timeout (TCP socket timeout (default value: 4 minutes) and sc-win32-status of 64
So essentially it appears that WCF code is taking a long time to respond and the client is timing out, what I observe in IIS log is just a symptom and not a problem.
The behavior you are describing will also occur if you exceed a WCF service's max sessions, calls or instances (depending on how you have your service instancecontext mode configured). If you observe the System.ServiceModel performance counters for %max concurrent sessions and/or %max concurrent calls (again depending on your service's instance context), you may see a correlation with the IIS log entries.
Note that these maxes can be configured in the service throttling behavior.
https://msdn.microsoft.com/en-us/library/vstudio/system.servicemodel.description.servicethrottlingbehavior(v=vs.100).aspx
I saw your question again and wanted to point out that I found a solution for this. It turned out to be this piece of code in the web.config:
<pages smartNavigation="true">
After turning this off I stopped receiving the same time-out errors. See also the answer here
IIS put the services into sleep to save recources.
Copied from here (WCF REST Service goes to sleep after inactivity)
The application pool hosting your service defines Idle Time-out property (advanced settings of app pool in IIS management console) which defaults to 20 minutes. If no request is received by the app pool within idle timeout the worker processes serving the pool is terminated. After receiving a new request the IIS must start the process again, the process must load application domain and all related assemblies, compile .svc file, run the service host and process the request.The solution can be increasing idle time-out but the meaning of this time-out is correct handling of server resources. If the process is not needed it should be stopped. Another ugly workaround is using some ping process (for example cron job or scheduled task on the server) which will regularly ping call some method on the service or page in the same application.