Built-in HA solution for WebSphere Message Broker/Message Queue

WebSphere Message Queue

WebSphere MQ V7 introduced an HA software support with the multi-instance feature.

The multi-instance capability provides an Active/Passive or Hot/Standby solution.
The queue manager in standby mode is not started but a daemon is monitoring a shared file system for lock file release.
When the active queue manager dies it frees the lock on the log files that allows the standby queue manager to start.

The file system has to support the necessary requirements:
Testing and support statement for WebSphere MQ multi-instance queue managers

General requirements for WebSphere Message Queue provides also information for the multi-instance support:
WebSphere Message Queue Support Requirements

Support on ritualized environment
http://www-01.ibm.com/support/docview.wss?uid=swg21392025

WebSphere Message Broker

WebSphere Message Broker leverages this WMQ capability and provides also a solution for Hot/Standby HA solution.


Here after you can find references that provides a very good introduction:

Configuring A Multi-Instance Message Broker For High Availability Support
Checklist for Implementing High Availability using Multi-Instances in Message Broker V7

To know more about

If you want to investigate in more details the HA solution please have a look to the following redbook:

High Availability in WebSphere Messaging Solutions

Tracing mapping node activity

Do you ever wanted to know what's happening in your mapping node.

This is related to the new mapping node introduced in WMB 8.

The debugger doesn't allowed you (for the moment?) to step into your mapping node. There is a way however to know what the broker is doing. Use the "User trace".

Say that your broker is MB8BRK and the execution group "default" and your flow that has a mapping node is deployed on this execution group.

execute the command:

mqsichangetrace MB8BRK -e default -u -l debug -r

-u state that it is a user trace

-l it is the level

-r is to reset your trace

more info at the infocenter

Send a message through your mapping node. The broker will produce a binary trace.

To read this trace execute the following command:

mqsireadlog MB8BRK -u -e default -o myXMLTrace.xml

This command will produce a xml file from the binary.

To have in a human readable format use the following command:

mqsiformatlog -i myXMLTrace.xml -o myTxtTrace.txt