Administrative functions for table/region maintenance

It would be useful to have some administrative functions available through HTable or HBaseAdmin. The two functions I'm thinking of right now are to force memcache flushes (on all regions, or individually specified) and to run major compactions (on all regions, or individually specified).

One reason to have this is currently major compactions run once a day by default. The time that they run is related to when you brought up your cluster or created the tables. In my case, this has been during peak load rather than offpeak times. We have times that we run other administrative tasks like backups, cleanup, etc... during off times, and this would be a good time to also trigger major compactions and memcache flushes.

Memcache force flushing can also be useful in the case that your cluster starts to have issues. They might be isolated to a single region or regionserver, but with lots of edits sitting in memcache and potentially unappended hlogs, you want to just flush things out to remove the possibility of losing anything.