Journaling actions

Journaling replicated libraries and other objects

If a replicated object is journaled on one node of a Db2® Mirrored pair, it is journaled on the other node as well. Start journal operations for libraries and other objects will be replicated if the object is replicated. If journaling of an operation fails for any reason on either node, including a journal not found error, the operation will fail on both nodes.

This means that if journals and journal receivers reside within libraries that are different from the objects being journaled, it is important to add replication for the journals before adding replication for the objects being journaled. By establishing the replication of the journals first, you will not have to manually intercede on the target to start journaling of objects. When a journal is replicated, a journal receiver is created and attached on the secondary node. In this way, the journaled objects can be used under commitment control from either node.

When actions that are taken on replicated objects are journaled, the journal entries are independent on each node and the source and target journal may not contain identical entries for all replicated object actions. For example, if a replicated object is changed, but the change does not succeed on one of the two nodes, Db2 Mirror may reverse the change on the node that was changed. You might see two journal entries on the node where the change succeeded and then was reversed, while there would be no journal entry on the side that failed.