Jobs preventing resume

Some jobs can prevent the resume of Db2® Mirror active replication. If this occurs, the list of jobs can be viewed using the Jobs Preventing Resume link in the Db2 Mirror GUI or by querying the MIRROR_SUSPENDING_JOBS table function.

Active replication between nodes will not resume until all jobs with Db2 Mirror database connections have completed their suspend processing for a previous suspend request. Allowing jobs to resume replication before completing their suspend processing could cause replicated objects to become out of sync.

If a resume request is unable to proceed because of jobs with pending suspend processing, you will see the Jobs Preventing Resume link displayed on the Home Page of the Db2 Mirror GUI. In this case, the replication detail of one of the nodes will show: (8660) - Suspended due to jobs existing which have not completed processing for a prior suspend. Clicking on the Jobs Preventing Resume link will display the list of jobs that are preventing the resume of active replication.

Figure 1. Home Page of Db2 Mirror GUI showing Jobs Preventing Resume link

Another way to view the list of jobs preventing a resume is to hover over the Health Center icon on the left side of the Home Page in the Db2 Mirror GUI and select Jobs Preventing Resume. Once selected, a list of jobs will be displayed if any jobs would prevent the resume of active replication.

Figure 2. Jobs Preventing Resume in the Health Center menu of the Db2 Mirror GUI

The Health Center - Jobs Preventing Resume GUI panel displays the list of jobs that are preventing Db2 Mirror active replication from resuming. There may be jobs on one or both nodes preventing the resume of active replication. The Db2 Mirror GUI attempts to display the jobs for both nodes. If unable to retrieve the results for one of the nodes, then a warning will be displayed and only the jobs for a single node will be shown. The Qualified Job Name column contains a clickable link which can be used to view the job log which can be used to further analyze what the job is doing.

Figure 3. Health Center - Jobs Preventing Resume display in Db2 Mirror GUI

Alternatively, the MIRROR_SUSPENDING_JOBS table function can be used to query which jobs are preventing the resume of active replication. Callers of the table function can retrieve results from the SOURCE, TARGET or BOTH nodes. See MIRROR_SUSPENDING_JOBS table function for more information.

Reasons why a job might prevent resume

Jobs will prevent the resume of active replication if they have not completed their processing of a previous suspend. Typically, jobs will recognize and quickly complete their processing of the suspension of Db2 Mirror replication. However, in some cases, a job may prevent the resume of active replication longer than expected. This may occur for the following reasons:

The job is held.
The job is executing a long running commit or rollback.
The job is executing a long running SQL statement like an ALTER TABLE or MERGE.

If a held job is preventing the resume of active replication, the recommendation is to release the job so that suspend processing can complete for that job. To release held jobs using the Db2 Mirror GUI, select one or more rows in the Jobs Preventing Resume table, right click to display a list of options, and select Release Job(s).

For jobs with a long running commit or rollback of a transaction, the recommendation is to allow the job to finish the committable work.

For jobs executing a long running SQL statement, the recommendation is to allow the SQL statement to finish.

If you are unable to wait for jobs to complete their pending work, you may choose to end some of the jobs that are preventing a resume. To end a job using the Db2 Mirror GUI, select one or more rows in the Jobs Preventing Resume table, right click to display a list of options, and choose End Job(s). It is recommended to allow all suspend processing to finish.

If after inspecting the jobs and performing any necessary actions, Db2 Mirror active replication still will not resume, it is recommended to contact support.