[HBASE-18598] AsyncNonMetaRegionLocator use FIFO algorithm to get a candidate locate request

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0-alpha-2, 2.0.0
• Component/s: asyncclient
• Hadoop Flags: Reviewed
• Release Note: Introduce FIFO algorithm to get a candidate locate request for AsyncNonMetaRegionLocator.
• Assignee: Guanghao Zhang
• Reporter: Guanghao Zhang
• Created: 15/Aug/17 07:18
• Updated: 01/Aug/18 06:20
• Resolved: 16/Aug/17 06:05

Description

// TODO: use a better algorithm to send a request which is more likely to fetch a new		
// location.

After this issue, the AsyncNonMetaRegionLocator will use FIFO algorithm to get a candidate locate request. Meanwhile, we will clear the completed requests before get a candidate.