[HDFS-15783] Speed up BlockPlacementPolicyRackFaultTolerant#verifyBlockPlacement

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3.1, 3.4.0, 3.2.3
• Component/s: block placement
• Labels: pull-request-available
• Assignee: Akira Ajisaka
• Reporter: Akira Ajisaka
• Created: 19/Jan/21 08:33
• Updated: 10/Jun/21 07:44
• Resolved: 21/Jan/21 01:14

Description

Set<String> racks = new TreeSet<>();
for (DatanodeInfo dn : locs) {
  racks.add(dn.getNetworkLocation());
}
return new BlockPlacementStatusDefault(racks.size(), numberOfReplicas,
    clusterMap.getNumOfRacks());

Here, HashMap should be used instead of TreeSet.

Issue Links

• relates to: HDFS-14102 Performance improvement in BlockPlacementPolicyDefault
• links to: GitHub Pull Request #2626