RabbitMQ Camel and STOMP - rabbitmq

I successfully completed a POC using Spring Reactor Netty Stomp client (Spring messaging framework) to connect to RabbitMQ on port 61613 (port dedicated for STOMP). That was just a POC. Now I have to build something concrete to be able to deploy in prod environments. I was Googling Spring Messaging vs Spring Integration and stumbled upon Apache Camel.
RabbitMQ component page in the Camel documentation talks about port 5672 and that is AMQP. The STOMP component page talks about ActiveMQ.
I did not see any examples or documentation regarding Camel in conjunction with RabbitMQ and STOMP.
Can Apache Camel be used to connect to RabbitMQ on port 61613?

The Camel documentation for the STOMP component states:
The Stomp component is used for communicating with Stomp compliant message brokers, like Apache ActiveMQ or ActiveMQ Apollo.
Notice that it says like Apache ActiveMQ. It doesn't say it has to be Apache ActiveMQ. It just uses ActiveMQ as an example of a "Stomp compliant" message broker. If RabbitMQ supports STOMP then Camel's STOMP component should work without issue.
Looking at Camel's StompEndpoint it clearly uses the brokerURL from the configuration to make the connection to the Stomp broker. It uses the Fusesource Stomp client implementation which should work with any Stomp compliant broker.
It's also worth noting that Camel is an integration framework and Stomp is a simple, open messaging protocol so it doesn't make much sense for the Stomp component within Camel to only work with a couple of ActiveMQ brokers. It can (and will) work with any Stomp compliant broker (just as the documentation states).

Related

Sending message from ActiveMQ Artemis to ActiveMQ "Classic"

I'm using Apache ActiveMQ Artemis (N1) for my work, and recently I've got a task to send some messages to another ActiveMQ "Classic" (N2) which is used by another system. However, I don't know how should I write divert configurations at broker.xml file. Is it possible? Could you give an example of divert to another URL-address and queue. Where should I write login/password for connection to N2?
Diverts in ActiveMQ Artemis only work with local resources. To send messages to another instance of ActiveMQ Artemis you'd use a core bridge. However, that only works between instances of ActiveMQ Artemis. ActiveMQ "Classic" doesn't support the protocol which the core bridge uses.
In order to send messages from ActiveMQ Artemis to ActiveMQ "Classic" you'd need to use something like Camel or the JMS bridge shipped with ActiveMQ Artemis. Both of these solutions can be deployed as web applications using the embedded web application server in ActiveMQ Artemis. We ship examples of both. The Camel example is in examples/features/standard/camel/ and the JMS bridge example is in examples/submodules/inter-broker-bridge.

Spring STOMP Broker Relay + RabbitMQ Cluster with HA Proxy fronting each for load balancing

I am designing a system where a huge number of real-time data generated from devices is to be transferred to subscribers preferably over websockets. I have decided to use Spring STOMP Websockets as it was quicker to set-up, understand and had a few things supported out of the box like RabbitMQ and Security. And also because the plan is to use Spring for another REST API so Spring as a choice of tech stack. RabbitMQ is the message broker that I have decided on. However I can not find good amount of guidance on how to scale such a system.
The possible solution I am thinking of is:
To add HAProxy in front of STOMP broker instances and also between
STOMP Brokers and a RabbitMQ cluster, HAProxy will act as a
load-balancer in both cases. Spring STOMP broker will then be pointing to the HAProxy as broker relay host. The requirement is to have high availability and no data loss.
As I do not have prior experience with Websockets, I would like to get guidance on if this solution sounds correct or if there is anything that I am missing here?
Note: In this system, both the message producers and consumers are actually websocket Java clients. I took the sample code from https://github.com/nickebbutt/stomp-websockets-java-client and created two separate clients - One that only sends the messages i.e. device data(Producers) and other that subscribes to these messages(Consumer). Thus both connect using same websocket URL to same STOMP broker. With above system implementation the clients will point to HAProxy for websocket connection.
Just an updated on this, I did experimentation by creating the above set-up and it worked i.e. I was able to connect to websocket stomp server/send/receive data with RabbitMQ broker and use of HAProxy load balancing as described. The broker host/port configured in Spring was pointing to HAProxy which in turn was forwarding requests to RabbitMQ backend. Similarly, the websocket clients were connecting to Spring STOMP websocket server application via HAProxy.

Spring+RabbitMQ make queues non durable

I am using RabbitMQ as a Stomp broker for Spring Websocket application. The client uses SockJS library to connect to the websocket interface.
Every queue created on the RabbitMQ by the Spring is durable while topics are non durable. Is there any way to make the queues non durable as well?
I do not think I can configure on the application side. I played a bit with RabbitMQ configuration but could not set it up either.
Example destination on RabbitMQ used for SUBSCRIBE and SEND:
services-user-_385b304f-7a8f-4cf4-a0f1-d6ceed6b8c92
It will be possible to specify properties for endpoints as of RabbitMQ 3.6.0 according to comment in RabbitMQ issues - https://github.com/rabbitmq/rabbitmq-stomp/issues/24#issuecomment-137896165:
as of 3.6.0, it will be possible to explicitly define properties for endpoints such as /topic/ and /queue using subscription headers: durable, auto-delete, and exclusive, respectively.
As a workaround you can try to create queues by your own using AMQP protocol and then refer to that queues from STOMP protocol.

RabbitMQ, is it possible to publish via one protocol and consume via another?

RabbitMQ supports multiple protocols, AMQP, MQTT, STOMP, ....
When using PHP for example, it's easier to publish using the STOMP library since the PHP AMQP libraries requires compiled C code and is somewhat of a mission to setup if you don't have to.
On the JAVA side, apache camel with AMQP on spring is pretty straight forward.
Is it possible to setup a queue, publish to it via STOMP and then consume via AMQP and then again publish via AMQP and consume via STOMP if the message broker is RabbitMQ?
Yes, this should work, given that you have installed RabbitMQ's STOMP plugin on your RabbitMQ node(s).
The protocol only defines the communication between client and server and has no impact on a message itself.
You should note that using protocols other than AMQP will most likely come along with limitations and/or worse performance.
There also exist native PHP libraries for RabbitMQ that don't require compiling C code. Unfortunately, I cannot tell you which one is the best, because I am a Java guy ;-).

Can I configure Apache ActiveMQ to use the STOMP protocol over UDP?

I'm developing a STOMP binding for Ada, which is working fine utilizing TCP/IP as the transport between the client and an ActiveMQ server configured as a STOMP broker. I thought to support UDP as well (i.e. STOMP over UDP), however, the lack of pertinent information in the ActiveMQ documentation or in web searches suggests to me that this isn't possible, and perhaps it doesn't even make any sense :-)
Confirmation one way or the other (and an ActiveMQ configuration excerpt if this is possible) would be appreciated.
this is not implemented in ActiveMQ at the moment as Stomp transport uses TCP only. It is possible to implement, so if you have a time to do it, give it a try.