I have one WCF service hosted in IIS 7.5. We observed that when we are making the first cal to the WCF service it is very slow. Taking almost 10 to 13 secs time to reach to WCF service. When turn on the tracing in the server we observed that it is taking time while creating the servicehost and open it. Please note we have done IIS level setting of StartupMode as AlwaysRunning but no luck so far. Due to this we are getting timeout exception for the first time as the client expecting the call to be finished within 6 secs. Second call onwards it is very fast as it is using the existing ServiceHost. Please let me know if by anyway we can reduce this time.
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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 am trying to debug performance issues with a .net 3.5 silverlight 3 - wcf service based application. the service is running under IIS 7 on a server that is not under heavy load
The problem is that certain actions in the application are taking a long time to complete, in an attempt to debug this we have added manual loggin into the silverlight and wcf application to time how long calls from the silverlight client take to reach the service, how long for the service to process, then how long for the response to reach the client
Are findings show that we seem to be getting large delays - up to 45 seconds between messages being sent and received to and from the server.
Unfortunately these large delays seem to be happening randomly, to different service calls we no pattern. The majority of the time calls work relatively quickl.
I believe this may be related to concurrent usage, as the issue appears to get worse when 4- 5 users are using the system at once.
Has anyone else experienced issues like this? And could anyone advise any usefull ways to debug this kind of issue or at least narrow down the possible causes?
When running in debug or via IIS locally on a development machine this issue does not occur
Thanks!
I have already asked a similar question here: WCF Service calling an external web service results in timeouts in heavy load environment but I've got a better idea now as to what's happening so posting a new question.
This is what is happening:
.NET client sends multiple requests at the same time to a WCF service (if it helps - I'm replicating this scneario by using Visual Studio Load Tests)
The client has got a "sendTimeout" set to 5 seconds
The WCF service receives it and start processing it. The processing involves sending a request to an external service which could take about 1 second to come back with a response
This is where I think the problem is: the client has sent many requests to the service and since the service is still busy processing the concurrent requests, some of the reqeusts from the client are timing out after 5 seconds
I have tried the following:
Changed the InstanceContextMode to PerCall
Increased the values of maxConcurrentCalls & maxConcurrentInstances
Increased the value of connectionManagement.maxconnection in machine.config
But none of that seems to be making any difference. Does anyone has any idea how can I ensure that I don't run into this timeout issue?
OK, you say WCF and that is not enough. What binding are you using and where are you hosting it? If you are using IIS, the could be different underlying problem than self-hosting.
The likely reason is the small number of ThreadPool size. You can use ThreadPool.SetMaxThreads() to change this but beware this is a sensitive value. Have a look here.
Check out the following link:
http://weblogs.asp.net/paolopia/archive/2008/03/23/wcf-configuration-default-limits-concurrency-and-scalability.aspx
I'm not sure what you're trying to achieve. Since the WCF service is doing a time consuming operation, you can't overload it and expect it to function. You can do the following (check the link about to set the following):
Increase the receiving capacity of the wcf service
Increase the send timeout of the service
Increase the send timeout of the client
Increase the receive timeout of the client
Limit the outgoing connections to the wcf service
The best and most robust option would be to configure and use MSMQ with the WCF service.
I've got a WCF client talking to a WCF server (on the same machine). We use netTcpBinding with message-level security (using a custom principalPermissionMode and a custom implementation of serviceCredentials). The service is marked with InstanceContextMode.PerSession.
The WCF service is self-hosted in a Windows service (not in IIS).
In order to fake keep-alive, we have a Ping method that the client calls every 15 seconds. We keep the client proxy open for the lifetime of the client program (because initializing the session is expensive in our case).
Despite this, the connection is dropped after 9 hours, 1 minute and a bit (in 10 test runs, 7 of them died after 9h1m6s).
The only thing of consequence in the WCF logs is a "SocketConnection aborted" message, followed by a varying set of exceptions, but usually including a "connection was in the faulted state" exception.
Is there some timeout in WCF, or in TCP/IP, that's causing this? Because I'm stumped.
After much tedious investigation: After about 9 hours, the WCF client re-authenticates with the service. Something I'm doing during the authentication step is killing the existing session.
From your comments above you were running the tests at the same time.
Were they also on the same server, using the same application pool?
If so a recycling of the application pool could have caused all the tests to stop at the same time.
I have 2 wcf services, 1 which polls the other service at regular interval.The service2 is hosted in no. of machines with the same configuration.
My problem is that whenever the poller service gets restarted, even though the service2 on other machines runs fine, i am not getting the response from those services (basically it gets timed out - getting SYSTEM.TimeOutException ). If I try to access the same service (service2) from some temp application (without restarting the service2) it gives response.
If I restart the service2, than it works fine, the service1 (poller service) gets the responses from all hosted services (Service2).
Dont know what is causing problem.
Regards,
Chirag
Attach VS to your wcf service which hangs. And find out if your connection is successful.
Do it with both services, so that you can debug the services at runtime.
If you're using a sessionful binding (netTcpBinding, wsHttpBinding), it's more than likely that you're not explicitly closing your client channel when you're done with it. This would cause the behavior you see, because the session takes a minute or so to time out if you don't explicitly close it, and the default max number of sessions is low (10)- the server will let new sessions stack up until old ones close. You can also adjust the service throttle on the server side binding to increase the max number of open sessions allowed, but you really should make sure your clients are getting cleaned up properly first.