[HDFS-9036] In BlockPlacementPolicyWithNodeGroup#chooseLocalStorage , random node is selected eventhough fallbackToLocalRack is true.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: J.Andreina
• Reporter: J.Andreina
• Created: 08/Sep/15 14:09
• Updated: 30/Aug/16 01:27
• Resolved: 12/Sep/15 12:12

Description

For example in below clusterMap

Writer = "/d2/r4/n8" which does not have local node.
Available nodes rack =

{"/d2/r4/n7","/d1/r1/n1","/d1/r2/n3","/d2/r3/n6"}

Current hierarchy in choosing node for first local storage replica is
1. Choose local machine (Not available)
2. Choose Local node group machine (Not available)
3. choose random

But instead of choosing random , should choose localrack node first(if fallbackToLocalRack is true, in example it is "/d2/r4/n7" ) else should go for radom node