Data groups are in an enabled state when they are created. An enabled data group may have active or inactive replication processes. MIMIX supports the concept of a disabled state for data groups in a replication environment. When a data group is disabled, it cannot be started, ended, switched, or audited. However, its configuration is retained so that the data group can be enabled and used again when needed.
In environments where multiple data groups exist within a single resource group, changes to data group configuration entries that identify objects to replicate are propagated to the data groups within a resource group entry as follows:
If the configuration entry changes are made from an enabled data group, they are propagated to all data groups within the resource group entry, including disabled data groups.
If configuration entry changes are made from a disabled data group, they are not propagated to the other data groups in the resource group entry.
Data groups associated with an application group may be enabled and disabled automatically as part of a switch procedure (SWTAG command). If an application group includes a data group that you do not want to participate in switching operations, you can change its data group definition to specify *NO for its Allow to be switched (ALWSWT) parameter.
Data groups can also be manually enabled or disabled with the Change Data Group (CHGDG) command.
The ability to disable and enable a data group can be beneficial in a variety of scenarios.
Disabling a data group is useful for test environments. If you create a data group for testing purposes, when testing is complete you can simply end and disable the data group until it is needed again instead of having to delete the data group to clean up your environment. This provides the benefit of retaining your configured data group object, file, IFS, and DLO entries while the data group is not needed. Additionally, the journal manager does not retain journal receivers that have not been processed by a disabled data group, which allows you to save storage space on your system.
In environments that do not use application groups and have non-switchable data groups configured to replicate in different directions, the ability to disable data groups can simplify starting replication. You can avoid having to start each data group individually by disabling the data groups whose direction is not what you want. Then you can simply start the remaining data groups and the MIMIX environment using the Start MIMIX (STRMMX) command.
By default, only enabled data groups are shown on the Work with Data Groups (WRKDG) display. You can display disabled data groups by specifying *ALL or *DISABLED on the STATE parameter. Disabled data groups are indicated by a status of D (in green).
Before a data group can be disabled, its replication processes must be ended (inactive status) and any constraints on target node objects that were previously disabled by MIMIX must be enabled. In environments that use the MIMIX® CDP™ feature, data group processes cannot be suspended at a recovery point before ending replication because the request to end the data group will clear any recovery point.
When a disabled data group is enabled, any pending entries must be cleared when the data group is started. Specify CLRPND(*YES) on the Start Data Group command.