Library redirection with remote journals

 

Library redirection provides a means for remote journals and any of their associated journal receivers to optionally reside in differently named libraries on the target system from the corresponding local journal and journal receivers on the local system.

You can specify library redirection by using one of the following:

When using the QjoAddRemoteJournal API, specify a different name in the Remote Journal Library name field or the Remote Journal Receiver Library field. When using the ADDRMTJRN command, specify a different name for the Target Journal Library parameter or the Remote Receiver Library parameter. When a remote journal is added, its journal type specification influences how much redirection you can specify.

Types of remote journals describes the various types of remote journals that can be added, as well as a description of their redirection characteristics.

If redirection is not specified, then the remote journal will reside in a library that has the same name as the library that contains the source journal.

Library redirection for the journal object must be specified when replicating the journal entries to a target system for any journal starting with the letter Q in a library starting with Q. This does not apply to the QGPL library. This restriction prevents collisions between local and remote journals that are used for system functions. One example of this is journal QAUDJRN in library QSYS which is used for security auditing.

If no redirection is specified for the journal receiver, then the remote journal receiver will reside in a library whose name is the same as the library for the source journal receiver. For example, the source journal has two receivers that are associated with it, receiver RCV0001 in library LIBA, and receiver RCV0002 in library LIBB. If no journal receiver library redirection is specified, then the journal entries in RCV0001 in library LIBA on the source will be replicated to RCV0001 in library LIBA on the target system. The journal entries in RCV0002 in library LIBB on the source will be replicated to RCV0002 in library LIBB on the target system. Therefore, both libraries, LIBA and LIBB, will need to exist on the target system prior to the invocation of the remote journal function. If journal receiver library redirection is specified with a redirected receiver library specification of RMTLIB, then both RCV0001 and RCV0002 would be in library RMTLIB on the target system.

For *TYPE1 remote journals, the library redirection or the selection of no library redirection for the journal and journal receivers can only be modified by doing the following:

  • Remove all *TYPE1 remote journals.

  • Change the local journal and attach a new journal receiver.

  • Delete the remote journal from the target system.

  • Add the *TYPE1 remote journal, specifying the new library redirection, if any.

For *TYPE2 remote journals, the library redirection or the selection of no library redirection for the journal and journal receivers can only be modified by doing the following:

  • Remove the *TYPE2 remote journal.

  • Delete the remote journal from the target system.

  • Add the *TYPE2 remote journal, specifying the new library redirection, if any.

 

Independent disk pools and library redirection

If you want the remote journal on an independent disk pool on the target system, specify a library on the target system that is on an independent disk pool for that system and specify an RDB entry for the independent disk pool.

If you place your remote journal on an independent disk pool on the target system, the following rules apply:

  • The independent disk pool on the target system must be varied on.

  • The independent disk pool must be a library capable disk pool.

  • The remote journal, the remote journal receiver, and the message queue must be in the same independent disk pool group.

  • When TCP communications are being used to connect to an independent disk pool, the Relational Database (RDB) entry to the independent disk pool must have the Relational database value set to the target system's local RDB entry and the relational database alias value set to the independent disk pool's name.

 

Parent topic:

Process of adding remote journal

Related concepts
Types of remote journals Journal management and independent disk pools

Related tasks
Preparing to use remote journals