[HDFS-13833] Improve BlockPlacementPolicyDefault's consider load logic

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.2.0
• Hadoop Flags: Reviewed
• Assignee: Shweta
• Reporter: Henrique Barros
• Created: 17/Aug/18 17:24
• Updated: 23/Oct/20 01:01
• Resolved: 19/Sep/18 03:24

Description

I'm having a random problem with blocks replication with Hadoop 2.6.0-cdh5.15.0
With Cloudera CDH-5.15.0-1.cdh5.15.0.p0.21

 

In my case we are getting this error very randomly (after some hours) and with only one Datanode (for now, we are trying this cloudera cluster for a POC)
Here is the Log.

Choosing random from 1 available nodes on node /default, scope=/default, excludedScope=null, excludeNodes=[]
2:38:20.527 PM	DEBUG	NetworkTopology	
Choosing random from 0 available nodes on node /default, scope=/default, excludedScope=null, excludeNodes=[192.168.220.53:50010]
2:38:20.527 PM	DEBUG	NetworkTopology	
chooseRandom returning null
2:38:20.527 PM	DEBUG	BlockPlacementPolicy	
[
Node /default/192.168.220.53:50010 [
  Datanode 192.168.220.53:50010 is not chosen since the node is too busy (load: 8 > 0.0).
2:38:20.527 PM	DEBUG	NetworkTopology	
chooseRandom returning 192.168.220.53:50010
2:38:20.527 PM	INFO	BlockPlacementPolicy	
Not enough replicas was chosen. Reason:{NODE_TOO_BUSY=1}
2:38:20.527 PM	DEBUG	StateChange	
closeFile: /mobi.me/development/apps/flink/checkpoints/a5a6806866c1640660924ea1453cbe34/chk-2118/eef8bff6-75a9-43c1-ae93-4b1a9ca31ad9 with 1 blocks is persisted to the file system
2:38:20.527 PM	DEBUG	StateChange	
*BLOCK* NameNode.addBlock: file /mobi.me/development/apps/flink/checkpoints/a5a6806866c1640660924ea1453cbe34/chk-2118/1cfe900d-6f45-4b55-baaa-73c02ace2660 fileId=129628869 for DFSClient_NONMAPREDUCE_467616914_65
2:38:20.527 PM	DEBUG	BlockPlacementPolicy	
Failed to choose from local rack (location = /default); the second replica is not found, retry choosing ramdomly
org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy$NotEnoughReplicasException: 
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseRandom(BlockPlacementPolicyDefault.java:784)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseRandom(BlockPlacementPolicyDefault.java:694)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseLocalRack(BlockPlacementPolicyDefault.java:601)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseLocalStorage(BlockPlacementPolicyDefault.java:561)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseTargetInOrder(BlockPlacementPolicyDefault.java:464)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseTarget(BlockPlacementPolicyDefault.java:395)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseTarget(BlockPlacementPolicyDefault.java:270)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseTarget(BlockPlacementPolicyDefault.java:142)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault.chooseTarget(BlockPlacementPolicyDefault.java:158)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1715)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:3505)
	at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:694)
	at org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.addBlock(AuthorizationProviderProxyClientProtocol.java:219)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:507)
	at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617)
	at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1073)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2281)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2277)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:422)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1920)
	at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2275)

This part makes no sense at all:

load: 8 > 0.0

Issue Links

• Blocked: HDFS-13910 Improve BlockPlacementPolicy for small clusters
• relates to: HDFS-15461 TestDFSClientRetries#testGetFileChecksum fails intermittently