The repair service subrange may show last completed as not available:
- DataStax Enterprise 6.7, 6.8
Typically, this issue is present when the last subrange repair task either:
a) failed, or
b) did not complete.
If the issue is a repair failure, then the opscenterd.log files should provide an indication as to why the last subrange repair task failed. Typical situations are nodes down during the repair or failures to stream for some reason. Again, start with opscenterd.log, and then you may have to look at the logs on the nodes where the streaming failed.
If the repair did not complete, then it could be because of a schema change:
2020-12-14 15:30:27,863Z [repair_service] INFO: Detected a table added schema change.
The Repair Service will pause for 5 minutes then the Repair Service will activate again.
This period of time is configurable with [repair_service].restart_period. (MainThread)
A schema change will force the subrange repair task to start over, thus the last completed will show not available since the last repair did not complete fully.
I think the main point to understand is that the last completed field is exactly that, the last completed. It's not the last successful completion, but the last subrange repair. Thus, if the last subrange repair did not complete in full due to an error or other issue, the last completed may state not available.