My goal is to define some API using REST arch style and spring boot in order to store messages to activemq message broker. I would like to have REST on top of message broker to have possibility to restrict message format. Actually the main goal is to allow only messages which contains all nessessary fields inside message payload.
Could you please suggest if it is rigth way to go and if there are any alternative ways to achive the goal?
Yes. This is a REST-to-Messaging Proxy design and can work just fine for the use case you described.
Alternatively, you could do the message inspection in the broker, but since this inspection sounds logic-related, it is best suited for something running outside the broker.
Related
I have to run two instances of the same application that read messages from 'queue-1' and write them back to another queue 'queue-2'.
I need my messages inside the two queues to be ordered by specific property (sequence number) which is initially added to every message by producer. As per documentation, inside queue-1 the order of messages will be preserved as messages are sent by a single producer. But because of having multiple consumers that read, process and send the processed messages to queue-2, the order of messages inside queue-2 might be lost.
So my task is to make sure that messages are delivered to queue-2 in the same order as they were read from queue-1. I have implemented re-sequencer pattern from Apache camel to re-order messages inside queue-2. The re-sequencer works fine but results to data transfer overhead as the camel routes run locally.
Thinking about doing it in a better way, I have three questions:
Does artemis inherently supports re-ordering of messages inside a
queue using a property such as sequence number.
Is it possible to run the routes inside the server? If yes, can you
give an example or give a link to the documentation?
Some artemis features such as divert (split) requires modifying
broker configuration (broker.xml file), is there a way to do them
programmatically and dynamically so I can decide when to start
diverting message? I know this can be accomplished by using camel,
but I want everything to be running in the server.
Does artemis inherently supports re-ordering of messages inside a queue using a property such as sequence number.
No. Camel is really the best solution here in my opinion.
Is it possible to run the routes inside the server? If yes, can you give an example or give a link to the documentation?
You should be able to do the same kind of thing in Artemis as in ActiveMQ 5.x using a web application with a Camel context. The 5.x doc is here.
Some artemis features such as divert (split) requires modifying broker configuration (broker.xml file), is there a way to do them programatically and dynamically so I can decide when to start diverting message?
You can use the Artemis management methods to create, modify, and delete diverts programmatically (or administratively) at runtime. However, these modifications will be volatile (i.e. they won't survive a broker restart).
Is there any way you can control the order delivery of messages in a topic in EMS or Tibco (using a JMS Topic Subscriber)? Something like the message selector, but instead of filtering to do ordering.
I would like to use a header like JMSXDeliveryCount, so that new messages will get a higher priority. I know that there's RedeliveryDelay, but that works only for queues, not topics.
Even JMSPriority could be an option if I can set it after getting the message with a topic subscriber. Can I do that? Maybe with a Java Code activity?
The broker will deliver messages in order as it receives them, but re-ordering messages is a distributed computing / EIP problem (see sequencer). The issue is the broker does't know how many messages are coming or how long to keep the window open for re-ordering messages. This activity is best done outside the broker in your application where that information is understood.
EIP frameworks and ESB's have done a nice job of standardizing a handler for this type of workflow.
ref: EIP Sequencer http://www.enterpriseintegrationpatterns.com/patterns/messaging/MessageSequence.html
JMSPriority is indeed an option, but it cannot be set on an already received message. The solution is to confirm the message and republished it with a different priority.
I am creating a hosted system where multiple customers can send messages. I am receiving thoses messages on a JMS queue.
Now, all processing is done in a similar way and I want my process to poll all incoming queues for messages and handle them. Is there a way in WSO2 ESB to subscribe to multiple queues?
If not possible, the workaround would be to create a seperate listener process for each queue and have this post the message to a central processing queue. But that seems to be a less clean solution (and I think it will scale worse than listening to multiple queues).
Any ideas on this?
If changes to activeMQ server is possible ie. if OP is able to influence the configuration to the server, something like ActiveMQ diverts could do the trick.
<divert name="prices-divert">
<address>jms.queue.ABC</address>
<forwarding-address>jms.queue.theone</forwarding-address>
<exclusive>true</exclusive>
</divert>
<divert name="prices-divert">
<address>jms.queue.xyz</address>
<forwarding-address>jms.queue.theone</forwarding-address>
<exclusive>true</exclusive>
</divert>
Basically, multiple diverts that converge the messages from multiple queues to the single queue. This method has advantage over the reading and writing to single queue-as mentioned by the OP and would in my view scale well as it is inbuilt feature.
You can define a sequence with all the required logic in it and then call it from multiple proxy services (each listening to a specific queue). Otherwise you can try something similar to this sample.
I'm trying to understand the principles of HornetQ as well as core/JMS messaging using this solution.
In my experimental app, I'd like my end-user application(client) to send messages to a HornetQ which will be read by a backend app. So far this is no problem and I love HornetQ.
But now, i'd like to send an "answer" message from the backend app back to the end-user. For this, I have the condition that no other client app should be able to read the answer message (let's say it contains the current bank balance). So user A should only fetch messages for himself and the same applies to any other user.
Is this possible using HornetQ? If so, how do I have to do it?
with hornetq (or any other message system) you always send to a queue, not to a specific consumer.
ON this case you have to create a queue matching your client.
This answer here will provide you some feedback on request-response where I won't need to repeat myself after this approach:
Synchronous request-reply pattern in a Java EE container
Messaging middleware solutions (JMS, Tibco, etc.) allow publish/subscribe with "topic" filtering using wildcards to subscribe to all messages of a certain "topic", e.g. SUBSCRIBE("ACCOUNT.*") topic allows you to subscribe to both "ACCOUNT.WITHDRAW" message and "ACCOUNT.CHECKBALANCE" message.
The problem is that such subscription also receives my own published messages.
I'm looking for a mechanism, similar to, say, UDP multicast loopback which can be turned ON or OFF by the transport layer without messing with the data being sent.
Is there a common, declarative (no custom code, configuration only) way to configure the middleware not to receive messages which that very same service instance has published? Ideally, this should also be able to filter out everything published by ALL servers (nodes) of the same "kind".
Thanks in advance.
The JMS API contains this option for TopicSubscribers, e.g. TIBCO EMS let's you create a consumer with the "noLocal" property. That means no messages published over the same connection, get consumed by clients on the same connection.
e.g. take a look here how to create a topic subscriber with the "noLocal" option:
https://docs.tibco.com/pub/enterprise_message_service/7.0.1-march-2013/doc/html/tib_ems_api_reference/api/javadoc/javax/jms/TopicSession.html
No one is answering, so I'll chime in (in a hand-wavey way).
I believe there's nothing in the JMS spec around controlling whether you get your own sent messages back on a topic receiver. So any capability like this would be a non-portable vendor feature. Especially for your second requirement (based on "kind" of JMS client versus some control based on the same connection doing the sending/receiving).
If you've got no flexibility to modify code or message content (properties), I think you've got no portable solutions. And likely no solution at all for that second "kind" requirement.
If you want to investigate vendor-specific options, you'll need to tell us which vendor you're interested in. You may get nothing, but there's no way to know without asking.