[HBASE-17251] Add a timeout parameter when locating region

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Component/s: asyncclient, Client
• Hadoop Flags: Reviewed
• Assignee: Duo Zhang
• Reporter: Duo Zhang
• Created: 04/Dec/16 13:28
• Updated: 08/Dec/16 07:50
• Resolved: 08/Dec/16 02:08

Description

Now we always use the default timeout configured for zk and meta.

I think it is reasonable to always use the same timeout when accessing zk and meta as the result will be shared by lots of threads. If we could do a successful fetching then the result will be in cache so it does not make sense to set the timeout to a very small value when fetching.

But I think it is also important to let the user request finish in time even if the user can only get a timeout exception. We should not block a user request longer than operation timeout.

So I think we could add a timeout parameter to the region locate method, and if the location can not be fetched in time, we will just finished the returned CompletableFuture with a timeout exception, but the actual fetching operation can still go on and use its own timeout config.