Spring custom response for graceful shutdown - spring

We are implementing the microservice architecture. Now we faced the issue, that when we terminate the server by k8s for spring web it responds nothing for gRPC it responds 504. We would like to customize this behavior to return 503 for both cases.
I read some topics about the graceful shutdown in spring but haven't found any useful information on how to customize this.

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OpenTelemetry: Context propagation using messaging (Artemis)

I wrote some micro-services using Quarkus that communicate via Artemis. Now I want to add OpenTelemetry for tracing purpose.
What I already tried is to call service B from service A using HTTP/REST. Here the trace id from service A is automatically added to the header of the HTTP request and used in service B. So this works fine. In Jaeger I can see the correlation.
But how can this be achieved using Artemis as messaging system? Do I have to (manually) add the trace id from service A into the message and read it in service B to setup somehow the context (don't know whether this is possible)? Or is there possibly an automatism like for HTTP requests?
I would appreciate any assistance.
I have to mention at this point that I have little experience with tracing so far.
There is no quarkus, quarkiverse extension or smallrye lib that provides integration with Artemis and OpenTelemetry, yet.
Also, OpenTelemetry massaging spec is being worked at the moment, because the correct way to correlate sent, received messages and services is under definition at the OTel spec level.
However, I had exactly the same problem as you and did a manual instrumentation that you can use as inspiration: quarkus-observability-demo-activemq
It will correlate the sent service as parent of receiving end.

Quarkus Microprofile Rest Client, how to handle errors differently

I have 2 Quarkus services, one acts as an Edge-service and the other one as a Downstream service, the communication is done through Quarkus MicroProfile Rest-API client. Now Downstream service may return some kind of Bad request error (4xx) state with Json body. my problem now is Edge service is throwing 500 error with WebApplicationException because of that, is there a way to populate same response code and body from Downstream Service to Edge Service ?
This exception is thrown by the default rest client ResponseExceptionMapper.
You should be able to disable it by adding the following property to application.properties:
microprofile.rest.client.disable.default.mapper=true
See the Default ResponxeExceptionMapper and ResponseExceptionMapper sections of the MicroProfile Rest Client specification.

How to make Spring Boot REST controller asynchronous?

My application is simple 3-tier Spring Boot rest web-service with usual synchronous endpoints.
But since the period of getting response from downstream system where my service sends requests is quite long (kind of 60 seconds), I need to add support of asynchronous REST calls to my service to save upstream systems from a response awaiting. In other words, if a response to a downstream system is going to take more than 60 seconds (timeout), then the upstream system break the connection with my service and keeps its doing...
But when the response come, my service using "reply-to" header from the upstream system will send the response to the upstream system.
All the things above are kind of call back or webhook.
But I didn't find any examples of implementation.
How to implement this mechanism?
How can I find more information?
Does Spring Boot have something to implement it out-of-box?
Thank you for attention!
You can use the #Async annotation from Spring. You will also need to enable in your application this by setting #EnableAsync.
An important note is that your method with the #Async annotation should be on a different class from where it is being called. This will let the Spring proxy intercept the call and effectively do it asynchronous.
Please find here the official tutorial.

Example of RabbitMQ with RPC in Spring Integration

After make a search about different ways to implement it, im stuck.
What im looking for is to realize this example (https://www.rabbitmq.com/tutorials/tutorial-six-spring-amqp.html) with Spring Integration.
I had found interesting post as this (Spring integration with Rabbit AMQP for "Client Sends Message -> Server Receives & returns msg on return queue --> Client get correlated msg") but didn't help me with what i need.
My case mill be a system where a client call the "convertSendAndReceive" method and a server (basede on Spring Integration) will response.
Thanks
According to your explanation it sounds like Outbound Gateway on the Client side and Inbound Gateway on the Server side pair is what you need.
Spring Integration AMQP support provides those implementations for you with built-in correlation functionality: https://docs.spring.io/spring-integration/docs/5.0.0.RELEASE/reference/html/amqp.html

Spring cloud bus - rabbitmq unavailability marks the instance DOWN

I use spring cloud config bus (rabbitmq) in my micro-service. Only purpose for me to use rabbitmq in my microservice is spring cloud bus... I have 2 questions below.
When I was experimenting, I found that spring expects rabbitmq to be UP and running during application start. Which is contrary to what Spring cloud evangelises... (Circuit breakers...) To be fair, even service discovery is not expected to be up and running before starting an application. Is there any sensible reason behind this...?
Say, I start my application when rabbitmq is up and running. For some reason, rabbitmq goes down... What I should be losing is just my ability to work with rabbitmq... instead, /health endpoint responds back as DOWN for my micro-service. Any eureka instance listening to heart beats from my micro-service is also marking the instance as down. Any reasons for doing this...?
To my knowledge, this is against the circuit breaker pattern that spring cloud has evangelised.
I personally feel that spring cloud config bus is not an important feature to mark an application as down...
Is there any alternatives to tell my spring boot micro-service that connection to rabbitmq is not a critical service?
Thanks in advance!

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