[HDFS-3439] Balancer exits if fs.defaultFS is set to a different, but semantically identical, URI from dfs.namenode.rpc-address

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 2.0.0-alpha
• Component/s: balancer & mover
• Assignee: Unassigned
• Reporter: Aaron Myers
• Created: 17/May/12 22:42
• Updated: 03/Dec/15 21:48
• Resolved: 03/Dec/15 21:48

Description

The balancer determines the set of NN URIs to balance by looking at fs.defaultFS and all possible dfs.namenode.(service)rpc-address settings. If fs.defaultFS is, for example, set to "hdfs://foo.example.com:8020/" (note the trailing "/") and the rpc-address is set to "hdfs://foo.example.com:8020" (without a "/"), then the balancer will conclude that there are two NNs and try to balance both. However, since both of these URIs refer to the same actual FS instance, the balancer will exit with "java.io.IOException: Another balancer is running. Exiting ..."