The Reporting Aggregation task is hanging at 50% completed (4318575)

The Reporting Aggregation task can hang at 50% for a long period of time or not finish.

The MessageStats database indexes are not in an optimal state.

Create and deploy a SQL Reindex job to reindex the MessageStats database on a regular basis.

Note: Before you reindex the database, ensure that no MessageStats Consoles attached to the database are currently writing information to the database. If you use the Database Management Utility while a MessageStats Console is writing to the database, you risk corrupting your database.

1. Open the MessageStats console
2. Expand Database Management | Database Maintenance
3. Select Reindex
4. Select Daily , Weekly , or Monthly from the Schedule type box
5. Enter a Start Date and Start Time in the respective boxes
6. Select the Limit Job Execution Time box if you want to limit the duration of a reindexing job, and enter an appropriate end time
7. Enter an appropriate recurrence interval
8. Click Deploy

After the Reindex job completes, open the MessageStats console and re-run a gathering and the Reporting Aggregation task will complete. The length of the time to complete will depend on the size of your database.