[HBASE-8777] HBase client should determine the destination server after retry time

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.94.9
• Component/s: Client
• Assignee: Unassigned
• Reporter: Sergey Shelukhin
• Created: 20/Jun/13 22:50
• Updated: 16/Jun/22 17:14
• Resolved: 04/Dec/13 19:00

Description

HBase currently determines which server to go to, then creates delayed callable with pre-determined server and goes there. For later 16-32-... second retries this approach is suboptimal, the cluster could have seen massive changes in the meantime, so retry might be completely useless.
We should re-locate regions after the delay, at least for longer retries. Given how grouping is currently done it would be a bit of a refactoring.

The effect of this is alleviated (to a degree) on trunk by server-based retries (if we fail going to the pre-delay server after delay and then determine the server has changed, we will go to the new server immediately, so we only lose the failed round-trip time); on 94, if the region is opened on some other server during the delay, we'd go to the old one, fail, then find out it's on different server, wait a bunch more time because it's a late-stage retry and THEN go to the new one, as far as I see.