Does MiniProfiler.WCF support asynchronous calls of WCF?
It seems that when calling our WCF service using our async interface AfterReceiveRequest on IDispatchMessageInspector is never triggered.
I believe this is due to the face that Async is not implemented in the whole WCF pipeline only at the operation level.
This led me to write a IParameterInspector and to start profiling in BeforeCall and AfterCall using OperationContext.Current.IncomingMessageHeaders and OperationContext.Current.OutgoingMessageHeaders to read and write the headers. This works fine on the host but on the client there will not be a OperationContext.Current so we cannot receive the headers.
AfterReceiveReply on the Client inspector is never triggered by async WCF so we can not get the headers from there either.
Has anyone made any progress in this area or does anyone have any advice about how we can get the timings back on the client?
Related
I currently have an application whereby a user makes a request to my ASP.Net UI, which in turns makes an async call into a WCF service to keep the ASP.net thread free.
The WCF service is essentially a translation module, sat on the restricted network, and bridging the DMZ to the Trusted network. This service calls out to a Java service, which will hit the DB, and I currently have this as a synchronous call.
My WCF services are setup with ConcurrencyMode.Single, and InstanceContextMode.PerCall, so I guess that when I run out of threads on the service host, I'll start backing up requests because the UI is calling async, allowing the user to send multiple requests.
Should I be calling the Java service as an async task, like I do in the UI?
async-await is almost always a good idea. It doesn't really matter which IO you are using (in this case a network call to a java service) as long as it can benefit from treating it as an asynchronous by releasing threads while waiting for IO to complete.
Of course you would get a bigger benefit by also making the java service fully asynchronous, but it isn't necessary.
How can I build a synchronous WCF service that wraps asynchronous MSMQ communications?
Let us have a simple scenario. I have a client which supports only synchronous web service calls. I need to send a synchronous request for "Order", but the back end system exposes this as an asynchronous request and response MSMQs. The WCF does not need to have any logic just wrap the MSMQ asych communication and pass parameters back and forth.
Grateful for your help
Let us have a simple scenario. I have a client which supports only synchronous web service calls
Synchronous call means you are using same link (end point url) or channel for your communication between client and server, so according to your assumption no.
Reason: Every time your client will send a request, it will keep waiting for response from server and will produce error.
Alternatively,You can define two services (different end point url) in your wsdl or webservice, one for request and one for response.
At client side you need to invoke these end point url saperately for sending request and receiving response,so it will appear as synchronous but ultimately it will be asynch. Thats all you can do in this scenario.
As per my understanding.
Can I listen to a WCF event from a web client? Is this possible? I am not talking about call backs, I want the WCF service to raise and event and the web client to be able to listen. Is there a good example of this in C#?
There are no events in WCF. If you want mimic event you still have to call some operation exposed on all clients = you must call WCF service or callback exposed on client.
What do you mean by web client? Do you mean javascript code running in web browser? In such case no you can't achieve that with WCF. You can only use AJAX calls from borowser and continuously poll the service for possible "event".
If you mean ASP.NET application then the answer is theoretically yes, practiacally it will be pretty hard. The reason is that in ASP.NET you handle only current HTTP request by some handler - for example Page. The lifetime of the handler is only for serving the single request. Due to that using duplex service doesn't make to much sense because for receiving callbacks by duplex service your client proxy must live. If you open the proxy in Page it will die after serving the request. If you open the proxy in separate thread you must somehow corelate incomming callbacks to actual client but the client still have to poll the web server to be notified about callbacks. Similar situation will be with exposing the service on ASP.NET application.
Difference between asynchronnous and duplex calls is big. In asynchronnous pattern single request always have single response. Resonse is not sent without request. In duplex pattern you can make single request and receive thousands callback from server.
I have a WCF service hosted as Windows Service with most of its methods currently defined as:
[OperationContract(IsOneWay = true)]
But, now I need to send response back to the calling Web application for these service methods.
Now, because service methods are bit heavy (FYI, they are reporting methods that needs to do mail merge for a no. of records), I am thinking to either queue them or to process asynchronously, so essentially when the request is sent to the service it should save the request to database/queue, returning Request-Id to calling Web application.
In the mean-time, WCF service can just process incompleted requests from the queue or database.
Then either calling Web application can ping WCF service for status of request because it has Request-Id or
WCF service can ping back to calling app when the process corresponding to a Request-Id is completed.
To achieve above, can anyone please guide what changes I need to make to my WCF service (which currently has all one way operation)?
Also, please guide me whether I need to go for Asynch operation or message queuing?
Thank you!
Of course, going Async is simple:
remove the OneWay on the OperationContract in question and regenerate your Service WITH Async methods. There's a reason why Silverlight forces you to use Async operations. They do force you to rethink your UI.
I have a WCF service client implemented using the asynchronous event (using /async and /tcv:Version35 in svcutil).
What is the best way to manage the service client?
I am creating a new service client on each request and closing the service client when the event delegate returns. Is it good practice to create a new service client on each request? If I try to use the same service client then I have to de-register the event handlers to every request once the request is furnished (which somehow does not look like an elegant way to achieve this).
if your services are stateless/sessionless then it's a good practice to create a service request and close/dispose them after use.
see this link on how to properly dispose a WCF service client