[HDFS-3377] While Balancing more than 10 Blocks are being moved from one DN even though the maximum number of blocks to be moved in an iterations is hard coded to 5

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 2.0.0-alpha
• Component/s: balancer & mover
• Assignee: Unassigned
• Reporter: J.Andreina
• Created: 07/May/12 04:48
• Updated: 07/Jun/12 03:55
• Resolved: 07/Jun/12 03:55

Description

Replication factor= 1,block size is default value
Step 1: Start NN,DN1
Step 2: Pump 5 GB of data.
Step 3: Start DN2 and issue balancer with threshold value 1

In the balancer report and the NN logs displays that more than 8 blocks are being moved from DN1 to DN2 in one iterations But MAX_NUM_CONCURRENT_MOVES in one iterations is hard coded to 5.
Balancer report for 1st iteration:
=================================

HOST-XX-XX-XX-XX:/home/Andreina/NewHadoop2nd/hadoop-2.0.0-SNAPSHOT/bin # ./hdfs balancer -threshold 1
12/05/03 17:31:28 INFO balancer.Balancer: Using a threshold of 1.0
12/05/03 17:31:28 INFO balancer.Balancer: namenodes = [hdfs://HOST-XX-XX-XX-XX:9002]
12/05/03 17:31:28 INFO balancer.Balancer: p         = Balancer.Parameters[BalancingPolicy.Node, threshold=1.0]
Time Stamp               Iteration#  Bytes Already Moved  Bytes Left To Move  Bytes Being Moved
12/05/03 17:31:30 INFO net.NetworkTopology: Adding a new node: /datacenter1/rack1/YY.YY.YY.YY:50176
12/05/03 17:31:30 INFO net.NetworkTopology: Adding a new node: /datacenter1/rack1/XX.XX.XX.XX:50076
12/05/03 17:31:30 INFO balancer.Balancer: 1 over-utilized: [Source[XX.XX.XX.XX:50076, utilization=5.018416429773605]]
12/05/03 17:31:30 INFO balancer.Balancer: 1 underutilized: [BalancerDatanode[YY.YY.YY.YY:50176, utilization=3.272819804269012E-5]]
12/05/03 17:31:30 INFO balancer.Balancer: Need to move 1.06 GB to make the cluster balanced.
12/05/03 17:31:30 INFO balancer.Balancer: Decided to move 716.13 MB bytes from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176
12/05/03 17:31:30 INFO balancer.Balancer: Will move 716.13 MB in this iteration
May 3, 2012 5:31:30 PM            0                 0 KB             1.06 GB          716.13 MB
12/05/03 17:35:29 INFO balancer.Balancer: Moving block -5275260117334749945 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:36:31 INFO balancer.Balancer: Moving block -8079758341763366944 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:37:12 INFO balancer.Balancer: Moving block -7395554712490186313 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:37:45 INFO balancer.Balancer: Moving block 7805443002654525130 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:38:15 INFO balancer.Balancer: Moving block 1864290085256894184 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:40:30 INFO balancer.Balancer: Moving block 23322655230037442 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:41:24 INFO balancer.Balancer: Moving block -8839566903692469634 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:43:03 INFO balancer.Balancer: Moving block 7304385435779271887 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:43:48 INFO balancer.Balancer: Moving block -7242009026552182303 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:44:06 INFO balancer.Balancer: Moving block -2449309138254106767 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:44:55 INFO balancer.Balancer: Moving block 500930296233438046 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.
12/05/03 17:45:04 INFO balancer.Balancer: Moving block 2642725820310610865 from XX.XX.XX.XX:50076 to YY.YY.YY.YY:50176 through XX.XX.XX.XX:50076 is succeeded.