We have WCF service running on IIS and would like to implement caching data for separate callers so that not each request for data would need to go to database. Is there a way to enforce IIS to create separte WCF service instance for different callers?
We use LAZY creation of the cache and from logging it seems that only one instance of service is created.
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I'm developing a UWP client project which need to consume some services of a WCF server. I uses the "add service reference" tool of Visual Studio to auto generate service clients(proxies). The binding type is NetTcpBinding. Below is some code snippet which create the service client:
NetTcpBinding tcpBinding = new NetTcpBinding();
tcpBinding.Security.Mode = SecurityMode.None;
tcpBinding.Security.Transport.ClientCredentialType = TcpClientCredentialType.None;
tcpBinding.Security.Message.ClientCredentialType = MessageCredentialType.None;
MainServiceClient = new MainServiceClient(tcpBinding, new EndpointAddress("net.tcp://localhost:8773/MyWCF/MainService/tcp"));
The question is do I need to call OpenAsync() method of MainServiceClient? It seems the service client can be auto opened when it is first called. But I read from this article that auto-opened service client would have some performance penalty. The article was written in 2007. I just wonder if this mechanism have changed today, especially in UWP project. Can anyone share more light on this topic? Thanks!
To explain this case, you should know three ways to do WCF instance management. WCF has provided three ways by which you can control WCF service instances:Per call, Per session, Single instance.
When we configure a WCF service as per call, new service instances are created for every method call you make via a WCF proxy client.
Very often we need to maintain state between method calls or for a particular session. For those kinds of scenarios, we will need to configure the service per session. In per session, only one instance of a WCF service object is created for a session interaction.
Often we would like to create one global WCF instance for all WCF clients. To create a single instance of a WCF service, we need to configure the WCF service as Single instance mode.
And there are three ways by which you can handle concurrency for each service instance in WCF :single, multiple, and reentrant.
Single: A single request has access to the WCF service object at a given moment of time. So only one request will be processed at any given moment of time. The other requests have to wait until the request processed by the WCF service is completed.
Multiple: In this scenario, multiple requests can be handled by the WCF service object at any given moment of time. In other words, requests are processed at the same time by spawning multiple threads on the WCF server object. So you have great throughput here but you need to ensure concurrency issues related to WCF server objects.
Reentrant: A single request thread has access to the WCF service object, but the thread can exit the WCF service to call another WCF service or can also call a WCF client through callback and reenter without deadlock.
In "Instance mode = Per Session and Concurrency = Single" combination, one WCF service instance is created for every WCF client session because the WCF instance mode is set to per session. All the method are executed in a sequential manner one by one. In other words, only one thread is available for all method calls for a particular service instance.
For the above scenario, you should always open WCF client proxy explicitly before you are making any calls. Because it will maintain service state between method calls and obtain high performance.
For more detail you could refer to "WCF Concurrency (Single, Multiple, and Reentrant) and Throttling" and "Three ways to do WCF instance management".
We have developed the wcf service with the existing web service code. the existing customer wants to consume that service only changing the new url. They do not want to replace the proxy class. is it possible in any case.
The customer is able to consume the same with replacing the proxy and config. but he does not want to replace the proxy. please share ur comments whether it is possible or not.
You may be able to do this by configuring an endpoint using basicHttpBinding. I believe you will also need to force the use of the XML Serializer, and I don't know how to do that offhand, so someone else will have to help you with that. I'm concerned that there could still be small differences that would cause errors using the same proxy class.
On the other hand, if performance isn't the top consideration, you could create an ASMX service using the original class and method attributes from the old service. This ASMX service would then call the WCF service.
BTW, the ASMX service could call the WCF service on a fast endpoint. If they were running on the same server, they could use netNamedPipesBinding, for instance, but in any case could use netTcpBinding, which uses binary over TCP/IP. That would mitigate the performance difference from the extra hop.
All,
I have developed a WCF Web Service and hosted it in IIS7.5. The service behavior is instanceContextMode=InstanceContextMode.PerSession and hence IIS creates an service instance during the first requests and creates as many instances as the number of requests.
But there is a requirement to cache some of the application data upfront before the service is invoked ie., similar to static initialization.
I don't want to disturb the service behavior attributes but want to achieve the static initialization.
I did try to use CustomServiceFactory and take up the load of creating service factory instances myself. But looks like the IIS will create the service factory as well during first request or I am not sure on this part.
So, I would like to know how to create the service instance / service factory instance when the application is deployed in IIS or during IIS restart?
Any help is much appreciated!
We are using the auto-start feature of AppFabric to initialize the services on application startup/app pool recycle. It invokes each service inside the application once during application start.
I want to create a service which receives a request from the client, adds the request to a database and than calls another WWF service ASYNCRONOUS which does some time consuming job withthe data from the database.
How do I make a service to be asincronous in Windows Workflow service?
I use the second Windows Workflow service as a queue(as it can only be one instance of this service=I set canCreateInstance to false).
To make a Workflow Service behave asynchronously create a One Way contract by using a Receive activity without a correlated SendReply.
When another Workflow (or WCF client proxy) calls this service it will not wait for a reply from the service.
As for your comment about only one instance of a service you are mistaken. There is no way to have a singleton workflow service (as there is with WCF services) and CanCreateInstance has no effect on this behavior.
I have a callback service that is hosted over wsDualHttpBinding. I'm looking to add a client that will poll for the data rather than receive the callback (will be a mobile device using wince for demo purposes). I was curious what the best way to do this is? You cannot create a client proxy using NetCFSvcUtil with a service hosted with wsDualHttpBinding (I understand that), but you cannot host a callback service over basicHttpBinding. I really need the same service hosted over both basicaHttpBinding (clients will poll for data) and wsDualHttpBinding (callback will notify clients of data). Any ideas on the best way to handle this without creating two separate services to host the same data?
What do you mean by two separate services hosting the same data? Do you expect to share same service instance to handle both wsDualHttpBinding and basicHttpBinding requests?
Your current problem is that service interface for duplex communication cannot be used for basicHttpBinding. You have to create second service contract and implement it in the same service. In that case you can expose two endpoints for the service: one duplex with WSDualHttpBinding and one with BasicHttpBinding. Endpoints must have different relative addresses. From the perspective of the client those endpoints are separate services - each of them requires separate client proxy. So unless your service is singleton you will have new service instance for each client proxy. New service instance means no data sharing.
Thera are some possibilities to modify this behavior but it means replacing Instance provider.