Using Docker containers; ASPNETCore 2.1.1 and NETCore 2.1; broker is RabbitMQ.
Our idea on during container/service startup, and RabbitMQ is down, is to try and capture the BrokerUnreachableException and try to call IHostedService.StartAsync() again after a period of time.
a. Where would we capture the exception?
b. Is this a good strategy?
Related
Spring boot Version : 2.5.0
Spring Cloud Version ： 2020.0.3
I used Spring-Cloud-stream-binder - Kafka and Spring-cloud-stream-binder - Kafka-Streams for kafka production and consumption in the project.
In one project, I subscribed to N topics.
Two nodes were started for service using load balancing.
During run time, it was suddenly discovered that one of the topics had no subscription nodes.
This results in messages being backlogged and lost.
I have to restart these service nodes before I can subscribe to this Topic again.
What is the cause of this, or is there any way to help find some clues.
And is there a way to check at run time so that topics that have lost subscriptions can be re-subscribed?
I'm thinking of developing a simulation of RabbitMQ that can be used in unit tests where it is not possible to start up an entire RabbitMQ server or not possible to connect to one. This RabbitMQ simulation would obviously have the same API as the RabbitMQ Java client. Question is now how to plug in this API of the RabbitMQ simulation into Spring Boot instead of the original one from RabbitMQ. Is there some hook in Spring Boot so that this could be done?
It's quite difficult to simulate RabbitMQ.
Some people have has some success using an embedded Apache QPID server running amqp 0.9.1.
However, it doesn't support any RabbitMQ extensions, if you are using those.
You'd be better off using something like TestContainers.
https://www.testcontainers.org/modules/rabbitmq/
I am using Spring-Kafka and using request/reply templates. I am noticing that after awhile I encounter timeouts when one service calls the other. The only way this seems to resolve is when I change topic name from request1, reply1 to request2, reply2 and redeploy both sides.... What am I missing in the configuration of the listener and or requester side? It seems the after a period of time it goes stale
We have configured our ActiveMQ message broker as a Spring Boot project and there's another Spring Boot application (let's call it service-A) that has a listener configured to listen to some topics using #JmsListener annotation. It's a Spring Cloud microservice appilcation.
The problem:
It is possible that service-A can have multiple instances running.
If we have 2 instances running, then any message coming on topic gets listened to twice.
How can we avoid every instance listening to the topic?
We want to make sure that the topic is listened to only once no matte the number of service-A instances.
Is it possible to run the microservice in a cluster mode or something similar? I also checked out ActiveMQ virtual destinations but not too sure if that's the solution to the problem.
We have also thought of an approach where we can decide who's the leader node from the multiple instances, but that's the last resort and we are looking for a cleaner approach.
Any useful pointers, references are welcome.
What you really want is a shared topic subscription which was added in JMS 2. Unfortunately ActiveMQ 5.x doesn't support JMS 2. However, ActiveMQ Artemis does.
ActiveMQ Artemis is the next generation broker from ActiveMQ. It supports most of the same features as ActiveMQ 5.x (including full support for OpenWire clients) as well as many other features that 5.x doesn't support (e.g. JMS 2, shared-nothing high-availability using replication, last-value queues, ring queues, metrics plugins for integration with tools like Prometheus, duplicate message detection, etc.). Furthermore, ActiveMQ Artemis is built on a high-performance, non-blocking core which means scalability is much better as well.
I am looking for a structure or solution that can support spring boot microservices with multiple instances, ActiveMQ Artemis and Apache Camel.
For example:
I have an ActiveMQ Artemis instance and a Spring Boot JMS consumer with instance A (on machine A) and instance B (on machine B).
Both instances (A,B) are up, but by default the instance A is the master consumer, I mean must consume the JMS message and only in case of it's down or it throw some exceptions, the instance B start consuming messages and when A is OK then it take the ball.
Nb: Instance A and B of the Spring Boot microservice are on different machine and in my case i don't have any container like docker etc...
Have you any approach to solve this issue.
I think the closest you could get to the functionality you want is by using the "exclusive queue" feature. Both consumers A & B can be active at the same time, but the broker will only send messages to one of them. If the consumer which the broker has chosen goes away for whatever reason then the broker will choose another consumer.