[HBASE-22039] Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.2.0, 2.3.0
• Component/s: Admin, asyncclient, Client
• Hadoop Flags: Reviewed
• Release Note: Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
• Assignee: Duo Zhang
• Reporter: Duo Zhang
• Created: 12/Mar/19 08:49
• Updated: 24/Jun/22 19:07
• Resolved: 16/Mar/19 02:21

Description

For now we always pass true to HMaster, maybe the decision is that user just do not need to calling get on the returned Future if it wants asynchronous.

But the problem here is that, the return value is not void, it is a boolean, which is the previous state of the flag, sometimes users do not need to wait until the previous transitions or split/merge to complete, but they still want to get the previous value of the flag.

So we still need to provide the synchronous parameter.