Is Service Broker External activator supported on managed instances? how to notify an external process like Webjob or Azure function? I am trying to avoid creating a CLR to call a webservice.
Service Broker External Activator requires Windows authentication, while Managed Instance supports only SQL and AAD authentication, so I guess that it cannot work.
Also, Service Broker External Activator reacts only on DDL events. If you need to implement notification on data changes you would need to create external app that uses change tracking, query notifications. However, if you need to call some external trigger from SQL engine, I guess that you cannot avoid CLR.
Related
After working with Oracle ADF for a while, I am now developing an application using Oracle Visual Builder. When calling REST services using the action chain component "Call REST", the call is visible in the browser console. (The services are added from the catalog, they are not defined by their specific endpoints)
Using Firefox's Inspection tools I can right click the request, edit it and resend it successfully despite the service using authorization.
In Oracle ADF I would simply call the service in a managed bean, the user wouldn't know I called it.
How can we not let the client/user know we called the service that in Visual Builder (or hide it from the console)?
Is there a way to call REST services other than the "Call REST" component in the Action Chain tools?
That's a key difference between the architecture of ADF that was running logic on the server, and VB that runs the logic on the client side.
Any web page that calls a REST endpoint (including from JS code) will show the REST call in the browser's log - this is not a VB specific behavior.
The security should be defined on the REST side requiring proper authentication to invoke the REST endpoint.
Maybe consider making the call from a custom JS function - and calling the JS function from the action chain?
Is it possible and allowable for MFP application to call web services directly without using adapters?
Yes. It's called making standard AJAX calls. Which means these calls will not benefit the features that are possible through MobileFirst (such as security, etc).
I have a good understanding SignalR Hubs in a client/server scenario, where both the client and server are tightly coupled.
Let's say I have a WCF service that receives an update from some external resource. That service could update the database with a new value. However the client would need to be notified that an update has occurred. This could be handled through a service proxy that notifies the client (sounds a bit like polling) or some cache resource.
I could create C#-based clients and connect all the nodes via SignalR hubs, but this creates a closed, non-distributed system.
A SignaR hub that attaches to a WCF service could use the .Net 4.5 could implement a WCF asynchronous service operation, where a hub client would be notified with any service data changes.
I saw something similar in Push Notifications with NServiceBus and SignaR, but not sure if this is an optimal production-level solution.
What other methods could be used in this scenario and how would they be implemented?
If you are not using push notifications directly to the client or some kind of long polling then it is pretty typical to communicate with clients on another channel altogether. Not knowing the business case, it is hard to tell what would be feasible. Usually this manifests itself in the form of SMS, push notifications to mobile, email, etc. This does not answer your question directly, but you may find that there is another way to achieve your goal.
What Works
I built a DataSnap web service in Delphi-XE2, which uses the TDSServer and TDSHTTPService components. Clients attach to the server (web service) and run DataSnap server methods to retrieve data. The server uses TDSLifeCycle.Session for all connections. I want to continue to use Session if possible because I store session information in thread variables...
I can use Internet Explorer to authenticate to and retrieve data from the DataSnap server. If I don't let IE sit idle for 30 seconds (or it disconnects from the server), it will reuse the same connection for every method request.
I can use a simple Delphi app that uses TIdHTTP to connect to the DataSnap server. Adding keep-alive to its Request.Connection property makes it stay connected forever and reuse the one connection for all method calls.
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Problem
A 3rd party company is building a WCF app to access the DataSnap service. They can't get WCF app to use only one connection to the service. The initial authentication request and 1st method call use the same connection, but subsequent requests create new connections, evident by running netstat on their computer and seeing new ESTABLISHED connections from their app to my service using multiple source ports. New connections create new threads in the DataSnap server, which can't access the authenticated thread's session variables.
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Possible Workaround
I know that I can change the DataSnap server to an Invocation model, making it unnecessary to maintain one persistent connection per client, and will do this if needed. Before doing so, I thought it prudent to see if anyone else knows how solve the problem.
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My Question
Is it possible for a WCF client app to create a single persistent connection to a non-WCF server (DataSnap server) that it uses for all method calls without it creating new connections? How is this done? Is it as simple as adding the right [decoration] to the C# WCF project in Visual Studio?
Any suggestions are greatly appreciated!
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FYI - I don't have access to the 3rd party's code, so I can't provide samples of the WCF code.
Your Delphi application provides a stateful web service (using session variables), and WCF web services are stateless by default, including WCF clients.
Maybe this answer points to the correct configuration (wsHttpBinding and SessionMode of the ServiceContract).
From the MSDN ocumentation:
For example, if the SessionMode property is set to
SessionMode.Required and the InstanceContextMode property is set to
PerSession, clients can use the same connection to make repeated calls
to the same service object.
(highlighting by me)
However, as DataSnap is not primarily designed for interoperability with WCF it might be easier to re-design the Delphi side to use a stateless web service model instead of stateful. This would require authentication with every service request, but internally the Delphi web service could some cache data to reduce lookup times, similar to the current session state.
I've got a static class library which I'm using to provide services to an ASP.NET MVC3 application.
I'm trying to get my head around the best way to provide async database calls. I've got an app that sends data to a node, which passes it on to all the nodes that node knows about and so on.
I'm using NServiceBus2 to accept a node message from a web client. Control is then sent back to the web app to allow the controller to finish and hence return the page to the user.
In the background a listener picks up that message and starts the node database trawl. I've created a new class library which is the listener which works fine.
My problem is publishing. Do I have to create the Bus on every call to a method? Where can I store the bus? I suppose I could try the WCF route?
Clarifications
I don't think it's a great idea to raise messages directly from a web application - in the same way you probably wouldn't put DB code in the controller. I'd like to have a separate class library that is the 'business logic'.
There are a couple of ways to get messages on the Bus from a ASP.NET web app. Firstly you can bootstrap the Bus once in a global place(global.asax or otherwise) and provide a reference to it. We prefer to reference the Bus via some abstraction, typically a class such as ServiceAgent<T> where T is a message you will internally Bus.Send(). If you don't want to boostrap the Bus in your web app, the other option is to expose your NServiceBus endpoint as a WCF service. This is done simply by implementing a class with the WcfService<TRequest,TResponse>. From there you can simply call the exposed SOAPy service. If you don't like SOAP, you can configure the endpoint differently. From within your endpoint you can then do a Publish().
you create a bus per service. a service can be a windows service, a win-forms application or in your case a website.
in a website/webservice scenario i normally create the bus in the application_start event of the global.asax.
you can save the bus in a container for example StructureMap or Castle Windsor.
don't publish messages from your website directly instead call a wcf service that publishes a message. or use send from your website. take your time to understand the different usages of messaging with nservicebus. specifically the differences of pub/sub and send/reply scenarios when to use what is essential.
to your other text: i don't understand your scenario. if you have further problems please edit your original post to help us understand.