A Message Queue 4.2 message broker will interoperate with one from Versions 3.0.x, 3.5, 3.6, or 3.7, and is able to migrate data from Versions 3.6 or 3.7. However, some changes have been made in broker properties and the persistent store schema. The degree of compatibility depends on the earlier Message Queue version from which you are upgrading:
Message Queue 3.7 data is fully compatible with Message Queue 4.2 and requires no migration.
Message Queue 3.6 data is generally compatible with Message Queue 4.2 and requires no migration.
Data from Message Queue 3.5 must be migrated by upgrading to Message Queue 3.6 or later before installing Message Queue 4.2.
When upgrading from Message Queue 3.6 or 3.7 to Message Queue 4.2, you can choose either of two approaches to handling the older versions’ instance configuration (config.properties) files:
Use the older config.properties files directly.
Copy the files to another location and consult the property settings they contain when you configure Message Queue 4.2 brokers.
Any persistent Message Queue 3.6 or 3.7 data (messages, destinations, and durable subscriptions) is automatically converted to Message Queue 4.2 data when starting up a Message Queue 4.2 broker for the first time. For example, existing destinations will be converted to Message Queue 4.2 destinations, preserving existing attributes and using default values for new attributes.
For Message Queue 3.6, the automatic upgrade leaves the original data intact in its original location. You can delete this data in either of the following ways:
Use the Broker utility’s -upgrade-store-nobackup option when starting up the Message Queue 4.2 broker for the first time:
Manually delete the old file-based persistent data store, located at
If you mix Message Queue 3.5, 3.6, or 3.7 brokers together with Message Queue 4.2 brokers in a cluster, the master broker must be of the oldest version in the cluster, and the cluster will run as a cluster of that oldest version.