I am new to WCF services, i have created a sample WCF service, where i have Hosted WCF Service with netTcpBinding in Windows Service.(since i want this WCF service to run as windows service)
Its a simple service which adds/deletes/loads employee details, and is consumed by a windows forms application.i don't know why, only 10 requests are responded, no matter what you do.The 11th request gives an error "request timed-out"
i know that increasing the time-out time wont help, it would just make me wait longer for that error.
i also know that my server(currently-local pc) is not responding for the 11th request, but don't know the reason.
Is there any setting for number of request/responses per minute for server? might sound funny, but i have no idea.
More useful info on the issue:
Can't change the binding other than nettcp (system requirement)
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It sounds like the connections aren't being closed - the default limit for WCF connections is 10, so the 11th won't work.
It might be that you're not explicitly closing them see here:
http://devcatharsis.blogspot.com/2008/09/wcf-refusing-connections-after-10.html
http://geekswithblogs.net/marcel/archive/2007/05/01/112159.aspx
Hope this helps.
Related
I built a application with 5 wcf services and hosted them in IIS 7.5. I used the default configuration for the net.Tcp port (808*).
I am not used to host WCF services in IIS (I always hosted in Windows Services) and I found interesting that when I call the service (using tcp binding) I got two different process on the server.
One is SMSvcHost.exe (the one that is actually using the 808 port) and the other is w3wp.exe wich I think is handling a instance of the server I am calling.
I have a lot of questions so I will enumerate them:
Should I use IIS instead of Windows Service to host WCF Services (tcp binding) ?
The fact that I have two processes to answer my request means that I may have cpu impacts ?
Sometimes my services stop answering using the tcp binding. I got a timeout error on my clients but the mex is correctly answering if I go to the http://myServer/Service1.svc. I suspect that this problem is caused by fault connections but I am throwing exceptions correctly (using fault exceptions) and catching them correctly on my clients. Besides, I am also implementing a partial class for every service to dispose corretly (either using Close or Abort methods). Is there any way to figure out what's going on when the services stop answering ?
Shouldn't the w3wp.exe processes be closed after the client ends the request ? They remain on the Task Manager even when no one is using the services. I guess this is the reason of why my Entity Library logging locks the file after my request is completed.
Ideally it would be better hosted in Windows Activation Services (WAS) which is close to what you think of as IIS, but not quite. Here's a good introductory article on MSDN magazine:
http://msdn.microsoft.com/en-us/magazine/cc163357.aspx
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 have a WCF service deployed as a windows service.
I have a website that tries to connect to this service and call one of its methods.
The service works fine and also responds with proper reply.
However, after some time (mostly after timeout) when I call one of the methods in the service, it returns a timeout error. The error tells me to increase send timeout of the binding. However, that doesnt work. I have also tried increasing the 'MaxItemsInObjectGraph' in the 'DataContractSerializerOperationBehavior' for the endpoint. But still the same error persists.
When I restart the service form the windows services, the requests are handled correctly. Again, after some time the scenario repeats. Expecting an answer for this soon. Thanks in advance.
I have a WCF service with netMsmqBinding. My client can send messages to my queue, and when the service is running it retrieves messages from the queue as expected. If the service is not running, messages received are queued until the service starts.
My problem is that the service does not start when a message hits the queue. The service is hosted in IIS, and so it is not instantiated until IIS receives a request. If I browse to the service then it processes the messages in the queue, but obviously this is not my desired method of processing the queue!
I expect that I need to change the service implementation, or change the IIS setup, but I do not know where or what to change.
UPDATE
Does anyone actually use MSMQ over WCF? I had this working for a short time - I enabled the binding on a different website on the same server, bizarrely - but now it has somehow stopped working again.
The only problem I am having is with the Activation of the service when there is a message in the queue. At present the queue only processes when the service is instantiated, e.g. when I browse the the .svc file. I have the net.msmq protocol enabled on the application, and I have the net.msmq binding enabled on the site... is there anything else I need to do?
You explicitly need to configure IIS for non HTTP activation. I don't know all the details of the top of my head but basically you need to use appcmd to configure and enable the net.msmq binding activation.
Check this blogpost or this screencast should give you all the details.
This might save somebody the hours it took me:
http://msdn.microsoft.com/en-us/library/ms731053.aspx
I believe that my problems using MSMQ binding over WCF were mainly around IIS.
I had no end of problems using Windows XP / Server 2003 with IIS 6.
Using Windows 7 or Server 2008 with IIS 7.5 everything works well.
An even better suggestion is to run MSMQ as a managed service / Windows Service or a stand-alone application rather than under IIS.
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.