Remote Journaling Setup

Remote journaling allows multiple copies of a journal and its receivers on more than one system. The following methods can be used to set up remote journaling: Cascade and Broadcast. Cascade replication sends only the journal entries to one remote journal. Broadcast replication sends the entries to up to 255 remote journals. Each remote journal can then be remotely journaled using either method, and so on. The source system can send to one additional system, that system can then send to three other systems, and so on.

Journal entries can be sent asynchronously or synchronously. Asynchronously sends the entries and immediately continues with the program; synchronous connections require that the remote systems acknowledge the entry before continuing. With asynchronous sends, the remote journal may be several entries behind the source.

Library redirection is the ability to decide what library holds the journal and receivers on the remote system. By default, the journal and receivers are named the same in the same library as the source system. However, the remote journal can be renamed and placed in a different library. The receivers may also be placed in a different library from the source system and in a different library from the journal.

To set up remote journaling, have your local environment set up and journaling started. Make sure you have a relational database directory entry for the remote system you want to journal to. Create an entry with WRKRDBDIRE command if required. Then, use the ADDRMTJRN command on the source to add the remote journal to the source journal. This command creates a remote journal and a receiver on the target box. A common misunderstanding is that a user must create the remote journal first, but that is not necessary because the ADDRMTJRN command does it for you. If using Broadcast, add additional remote journals using this same process. This command creates only the journal on the remote system.

By default, the remote journals are inactive. The state must be manually changed to *ACTIVE using the CHGRMTJRN command. When you activate a remote journal, all the entries in the current receiver are sent to the remote system. Depending on the size of the currently attached receiver on the source system, this step may appear to hang. In reality, the current receiver is simply sending all the current entries to the remote system. Detached receivers are not sent to the remote system. They must be manually moved, if required.

Example:

WRKRDBDIRE from SystemA shows
SYSTEMA as *LOCAL
SYSTEMB as 10.10.10.10.10.5

SystemA has a local journal JRNLIB/JRN1. To have these receivers sent to SystemB to the same library (JRNLIB) issue the following:

ADDRMTJRN RDB(SYSTEMB)
SRCJRN(JRNLIB/JRN1)
TGTJRN(*SRCJRN)
RMTRCVLIB(*SRCRCVLIB)

If you would like the journal and journal receiver to go to a different library on SystemB issue:

ADDRMTJRN RDB(SYSTEMB)
SRCJRN(JRNLIB/JRN1)
TGTJRN(JRNLIB@R/JRN1)
RMTRCVLIB(JRNLIB@R)

Then use the CHGRMTJRN to active the remote journal and start sending journal receiver to SystemB.

For more in-depth information on any step or item, consult the Backup and Recovery manual.