[HBASE-16398] optimize HRegion computeHDFSBlocksDistribution

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.0, 2.0.0
• Fix Version/s: 1.4.0, 2.0.0
• Component/s: regionserver
• Assignee: Lijin Bin
• Reporter: Lijin Bin
• Created: 11/Aug/16 09:41
• Updated: 01/Jul/22 20:29
• Resolved: 16/Dec/16 06:07

Description

First i assume there is no reference and link in a region family's directory.
Without the patch to computeHDFSBlocksDistribution for a region family, there is 1+2*N rpc call, N is hfile numbers, The first rpc call is to DistributedFileSystem#listStatus to get hfiles, for every hfile there is two rpc call DistributedFileSystem#getFileStatus(path) and then DistributedFileSystem#getFileBlockLocations(status, start, length).
With the patch to computeHDFSBlocksDistribution for a region family, there is 2 rpc call, they are DistributedFileSystem#getFileStatus(path) and DistributedFileSystem#listLocatedStatus(final Path p, final PathFilter filter).
So if there is at least one hfile, with the patch, the rpc call will less.