Balancer: number of nodes to be included = 0

Jeff P — Thu, 05 Nov 2015 18:49:36 GMT

Using Enterprise CDH 5.2.0, we just added a new data node. When attempting to run the rebalancer, it succeeds right away but does not balance the cluster.

The existing data nodes still have 10x the data as the new node.

Am I reading the log wrong, or is it not including any nodes when rebalancing? Do I need to configure which nodes should be included? Here is the log:

2015-11-05 18:29:19,766 INFO  [main] balancer.Balancer (Balancer.java:parse(686)) - Using a threshold of 10.0
2015-11-05 18:29:19,768 INFO  [main] balancer.Balancer (Balancer.java:run(544)) - namenodes  = [hdfs://nameservice1]
2015-11-05 18:29:19,768 INFO  [main] balancer.Balancer (Balancer.java:run(545)) - parameters = Balancer.Parameters[BalancingPolicy.Node, threshold=10.0, number of nodes to be excluded = 0, number of nodes to be included = 0]
Time Stamp               Iteration#  Bytes Already Moved  Bytes Left To Move  Bytes Being Moved
2015-11-05 18:29:20,506 INFO  [main] net.NetworkTopology (NetworkTopology.java:add(419)) - Adding a new node: /default/10.81.128.198:50010
2015-11-05 18:29:20,506 INFO  [main] net.NetworkTopology (NetworkTopology.java:add(419)) - Adding a new node: /default/10.81.128.197:50010
2015-11-05 18:29:20,507 INFO  [main] net.NetworkTopology (NetworkTopology.java:add(419)) - Adding a new node: /default/10.81.128.195:50010
2015-11-05 18:29:20,507 INFO  [main] net.NetworkTopology (NetworkTopology.java:add(419)) - Adding a new node: /default/10.81.128.196:50010
2015-11-05 18:29:20,508 INFO  [main] balancer.Balancer (Balancer.java:logUtilizationCollection(349)) - 0 over-utilized: []
2015-11-05 18:29:20,508 INFO  [main] balancer.Balancer (Balancer.java:logUtilizationCollection(349)) - 0 underutilized: []
The cluster is balanced. Exiting...
05-Nov-2015 18:29:20     Balancing took 1.054 seconds

Re: Balancer: number of nodes to be included = 0

Harsh J — Sun, 08 Nov 2015 15:30:28 GMT

Could you attach the 'sudo -u hdfs hdfs dfsadmin -report' command output?

Per the reported log, the Balancer seems to think all of the 'DFS Used%' values of each DN are well within 10% of each another, and it considers the DNs balanced. (P.s. Yes, it works on % used, not raw byte balancing).

Re: Balancer: number of nodes to be included = 0

Jeff P — Mon, 09 Nov 2015 16:20:52 GMT

Thanks. That was my issue. The nodes are balanced in terms of DFS Used%, even though the amount raw bytes are varied.

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Balancer: number of nodes to be included = 0

Re: Balancer: number of nodes to be included = 0

Re: Balancer: number of nodes to be included = 0