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384 Patterns: Implementing Self-Service in an SOA Environment

11.6 System management for JMS

This section takes a brief look at system management issues when using JMS

applications.

11.6.1 JMS performance issues

Some issues that play a role in JMS messaging performance are:

򐂰 Generic versus specific message structure

Making the message structure more generic requires more translation and

interpretation time at the sender and receiver ends. Making a message too

specific reduces flexibility for even small changes in the message structure.

Remember to create an error queue for messages that cannot be validated.

򐂰 Message persistence

Using persistent messages requires writing the messages to disk, which

takes time, reducing performance.

򐂰 Request/reply scenario

In a request/reply scenario, it is important that the issue of blocking calls is

dealt with correctly. Essentially, EJBs should only be used with appropriate

request/reply timeouts and retries.

򐂰 Message-driven bean

Minimize the time spent in a message-driven bean processing the message.

This will make message-driven bean processing faster. Let the pool of

message-driven beans depend on the number of messages that arrive at the

queue.

򐂰 Optimization with connection

Start the connection when appropriate so that consumers are ready to

consume messages before the producers are started. Also process

messages concurrently using a server session pool for the processing of the

messages. Close the connection when you are finished consuming

messages.

11.6.2 Performance monitoring for mediations

When PMI is enabled, the following information is collected for each mediated

destination:

򐂰

Mediation time is the time taken to perform the mediation.

򐂰

Messages mediated is the number of messages mediated at this destination.

Chapter 11. JMS scenario 385

򐂰

Thread count is the number of threads in the mediation thread pool

performing work for the mediation.

To enable these counters, perform the following tasks:

1. Select Monitoring and Tuning → Performance Monitoring Infrastructure

(PMI).

2. Click the server name.

3. Click the Runtime tab.

4. Click Custom.

5. Expand SIB Service → SIB Messaging Engines → <messaging

engine> → <mediation_name> → Destinations.

6. Click the queue destination. See Figure 11-12.

7. Check the boxes to the left of the counters and click Enable.

Figure 11-12 Enable the mediation counters

8. Click Thread Usage under Destinations.

9. Check the box to the left of ThreadCount and click Enable.

To view the counters, perform the following steps:

1. Select Monitoring and Tuning → Performance Viewer → Current activity.

2. Click the server name.

3. Expand Performance Modules → SIB Service → SIB MessagingS

Engines → <message_engine> → <mediation_name>.

See Figure 11-13 on page 386.