Java – JMS Topic message size

jakarta-eejavajms

Our application uses a topic to push message to a small set of subscribers. what sort of things should i look for when modeling a jms message with respect to the size of the actual message to be pushed. Are there any known limits or is application server specific? Any best practices or suggestions on this topic (pun unintended)?

Best Answer

You are likely to hit practical limits before you hit technical ones. That is, message lengths may have technical limits in the lengths that can be expressed in an int or long, but that's unlikely to be the first constraint you hit.

Message lengths up in the Megabytes tend to be heavyweight. Think in terms of a few K as the sort of ballpark you want to be in.

A technique used sometimes is to send small messages saying "Item 123435 has been updated", consumers then go retrieve data associated with Item 12345 from a database or other storage mechanism. Hence each client can get only the data they need, we don't spray large chunks of data around when subscribers may not need it all.

Related Solutions

Java – Post a message to a remote JMS queue using JBoss

You'll need to use JMS, create a QueueConnectionFactory and go from there. Exactly how you create the QueueConnectionFactory will be vendor specific (JMS is basically a driver spec for message queues just as JDBC is for databases) but on IBM MQ it something like this:

MQQueueConnectionFactory connectionFactory = new MQQueueConnectionFactory();
connectionFactory.setHostName(<hostname>);
connectionFactory.setPort(<port>);
connectionFactory.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
connectionFactory.setQueueManager(<queue manager>);
connectionFactory.setChannel("SYSTEM.DEF.SVRCONN");

QueueConnection queueConnection = connectionFactory.createQueueConnection();
QueueSession queueSession = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);

Queue queue = queueSession.createQueue(<queue name>);

QueueSender queueSender = session.createSender(queue);
QueueReceiver queueReceiver = session.createReceiver(queue);

EDIT (following question edit)

The best way to access a remote queue, or any queue for that matter, is to add a Queue instance to the JNDI registry. For remote queues this is achieved using MBeans that add the Queue instance when the server starts.

Take a look at http://www.jboss.org/community/wiki/UsingWebSphereMQSeriesWithJBossASPart4, which while it's an example with IBM MQ, is essentially what you have to do to connect to any remote queue.

If you look at jbossmq-destinations-service.xml and org.jboss.mq.server.jmx you'll see the MBeans you need to create in relation to a JBoss queue.

Java – Determine number of subscribers per topic in JMS

This sort of information isn't going to be available via the JMS API itself. You may have better luck talking to the JMS implementation's native API, although you don't mention what that implementation is.

Best Answer

Related Solutions

Java – Post a message to a remote JMS queue using JBoss

Java – Determine number of subscribers per topic in JMS

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