I want to setup instrumentation for bytebuddy for my REST services. Jax-rs services is running on remote host. I want to run a separate process on some other machine which will attach a java agent to the running service and should do the following.
Print something whenever it enters an actual rest method.
Send some other response like 401,402 .... without hitting REST service
Trace flow on each method enter and exit so as to come up with automatic flow chart based on a code flow for any user activity
I am not sure how to setup bytebuddy for the above use cases. Any pointers please ...
Related
Is it possible to write a ktor test without any client call? We have a ktor kafka consumer service that executes http calls. The shape of our test is:
startAndConfigureWiremock()
testApplication{
application{
changeConfiguration()
}
sendKafkaMessage()
verifyExternalCall()
}
but the tests with any client calls do not work. Test code verifyExternalCall() is executed before the service is up and blocks the startup without any testBlocking.
When we try to add parallelism like GlobalScope.launch it runs the application, but it just starts and stops.
Looks like testApplication needs a client call to work at all and even ktor test relay on it: https://github.com/ktorio/ktor/blob/8b784f45a6339728ce7181498a5854b29bf9d2a5/ktor-server/ktor-server-core/jvmAndNix/test/io/ktor/server/application/HooksTest.kt#L81
This might not be the answer you are looking for but...
This definately looks like the incorrect place and method for performing this test.
Ktor is for building web APIs, it is for dealing with things like routing and serialisation. Why are you testing if an internal service is being started and is polling kafka for messages? This has nothing to do with ktor.
If you really want to do an integration test on this service rather:
do not start ktor
start kafka
start your Kafka polling service
send your message
do your verification
If you really want to check that your kafka service is started by your ktor application just do a verification that some "startKafkaConsumer" function was called in your start up. This should most likely be done on some injected mock of your consuming service.
I have 2 web apps. One web app acts as a host (lets label as Host). All Web APIs resides here. Then the other web app calls those Web APIs (lets label as Client).
What I'm trying to accomplish is this:
Client calls a Web API using Jquery Ajax in Host and host processes this. After successful process, I want to be able to send some message in the HOST's client-side so I can update some UI.
That's the part I am unsure about. To notify the client-side of the Host so I can do some changes in UI, when the caller is in another app. I can't think of a way to pass some message so I can raise some popup, change some text, etc.
What I'm trying to accomplish is this: Client calls a Web API using Jquery Ajax in Host and host processes this. After successful process, I want to be able to send some message in the HOST's client-side so I can update some UI.
To achieve the requirement, you can try to integrate SignalR functionality into Apps.
Clients can connect to hub server, and clients can be added to two different groups, which provide a method for broadcasting messages to specified subsets of connected clients.
For more information about ASP.NET Core SignalR, you can check following docs:
https://learn.microsoft.com/en-us/aspnet/core/signalr/introduction?view=aspnetcore-3.1
https://learn.microsoft.com/en-us/aspnet/core/signalr/groups?view=aspnetcore-3.1#groups-in-signalr
This is a different question than my previous post on testing WCF.
This time after I've created my service, I want to test it not via WSDL, but I want to send an ajax request using $.ajax via jQuery.
I'm not sure how to wire up the service so that it's ready to recieve requests. Do I need the service setup and running in IIS? Or is there a way I can run the WCF project to run the service and then somehow in my NUnit Unit test create the jquery to make an HttpRequest..meaning would it know that the service is up and running? how?
You can host your service in the IIS, As a windows service or in a console app. To me it sounds wrong to call the service in a Unit test. Normally you mock out all external dependencies in a Unit test.
I have read Why not publish NServiceBus messages from a web application and another similar question about this but I am not clear if this applies to service layer as well. For example, if the service layer is composed of web services or REST services built using WCF or Web API or any other way, should those services publish events or send commands? If those services are hosted in load balanced web servers, the problems outlined in the articles apply to this layer as well. How would the recommendation change or not change?
If I look from the definition of Event vs Command, the messages I am talking about are Events e.g. "a user was created" and so an event should be published. As a matter of fact, the service that created the user doesn't even know what else to do i.e. may be another application is supposed to create a customized portal for it and yet another application is supposed to send a welcome kit to the user. This would be an event and not a command. I guess I am hung up on the definition of a web application and application service when application service itself is composed of one or many web applications.
The definition of Web Application
A web application is an application that is accessed by users over a
network such as the Internet or an intranet.
However, to me, the users can be computers and thus web services are web applications and that is the reason for this question.
EDIT:
Let's consider a concrete example. An ASP.NET website (MVC or Web form - doesn't matter) displays the form to the operator, gets a post with data about user creation (Name, UserName, Password) and invokes a WCF service to create the user. In between website and WCF service we can put ServiceBus and send command to create the user (Request/Response) so that we get all the benefits described in the first article. WCF service is the actual business processing layer i.e. it would create the user. That is where I have the question. After the user is created, it should announce that a user has been created and other systems can react to it and do whatever they are supposed to do. So it fits perfectly the pattern of publish the message. However, the WCF service itself is a web application and thus has most of the traits of the web applications and thus the confusion.
As mentioned in the answer to the SO question you linked to, publishing event has more to do with where the actual processing takes places. Just as a side-note: it is not a matter of Send instead of Publish since that would imply that the two are interchangeable whereas they have rather different intentions. When you want to publish, you want to publish.
The same questions should arise if you find yourself publishing from your web-exposed integration layer: should you be performing the business processing in that code or rather sending it off to another endpoint for processing? Typically you should just send it off to another endpoint. You may even consider how you would perform the relevant action should anyone wish to invoke it. For instance, if you are publishing a UserCreatedEvent message it implies that you created a user. How would a user be created? Would I be forced to use the WCF / Web-Api layer or can I send a CreateUserCommand message on the bus that is processed by some application endpoint? If it is the former then you may need to rethink your design. However, if the latter you should be sending the command from your WCF / Web-Api anyway and the processing endpoint will perform the Publish bit :)
update:
My take on it is that it is more about cohesion / concerns. You would typically interact with your domain, from within your business, via a service bus for commands and events, and a simple query layer for reads. If you need to expose anything to a third-party (or simply via the web) then you use WCF / WS / Web-APi. The point is that you should try to avoid business processing in an integration endpoint (or in a front-end like a website). Business processing is better suited to application servers. There are usually exceptions to the rule but if you are in a position to influence the structure then you are in a better space.
The fact is, whatever code is truly responsible for performing the action should be the same which publishes the event. If you've got a MVC app and in the controller itself you're using Entity Framework to insert the User record, then that is exactly where the Publish should be, right after the SaveChanges call. If however, the controller calls a referenced binary or service which does the actions involved in the "add user" call, then the Publish should be there. My thought is the event should be right alongside the code that does the action whose event you are trying to publish.
I have a Silverlight application which connects to a WCF service. Sometimes the WCF service contract gets updated while a user is still using the application, in which case the user would need to refresh the page to download the latest Silverlight client.
I would like to detect when the service contract gets updated and display a prompt in the browser that says something to the effect of "New update detected - please refresh the page." I could use a try/catch block to handle CommunicationException, however that is a very generic exception that could happen for any number of reasons.
What is the best way to detect a contract mismatch?
the best is if you could have some operation GetServiceVersion() which the client can periodically poll (if you can push it to the client even better). If the server cannot "cooperate" then the client has to download the wsdl and see if it changed, try to avoid that.