Hadoop中DataNode没有启动解决办法

查看从节点机器hadoop中datanode的log文件 , 拉到最后 , 报错如下

2017-11-22 13:51:17,114 WARN org.apache.hadoop.hdfs.server.common.Storage: java.io.IOException: Incompatible clusterIDs in /home/grid/hadoop-2.7.2/dfs/data: namenode clusterID = CID-edebd8f9-ab63-4a20-a78b-f48facee4fc8; datanode clusterID = CID-f74e6565-1141-42a7-bb05-ee30224d187e
2017-11-22 13:51:17,117 FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool <registering> (Datanode Uuid unassigned) service to /10.6.5.7:10000. Exiting.
java.io.IOException: All specified directories are failed to load.
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:478)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initStorage(DataNode.java:1358)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initBlockPool(DataNode.java:1323)
at org.apache.hadoop.hdfs.server.datanode.BPOfferService.verifyAndSetNamespaceInfo(BPOfferService.java:317)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.connectToNNAndHandshake(BPServiceActor.java:223)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:802)
at java.lang.Thread.run(Thread.java:748)
2017-11-22 13:51:17,137 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Ending block pool service for: Block pool <registering> (Datanode Uuid unassigned) service to /10.6.5.7:10000
2017-11-22 13:51:17,251 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Removed Block pool <registering> (Datanode Uuid unassigned)
2017-11-22 13:51:19,252 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Exiting Datanode
2017-11-22 13:51:19,253 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 0
2017-11-22 13:51:19,288 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at db2/10.6.5.30
************************************************************/

此原因是namenode和datanode的clusterID不一致导致datanode无法启动.

产生的原因是多次hdfs namenode -format , 每一次format,namenode都会生成新的clusterID , 而datanode还是保持原来的clusterID.

解决办法:

cat hadoop-2.7.2/dfs/name/current/VERSION 复制namenode的clusterID.

用该clusterID把所有datanode节点机器中hadoop-2.7.2/dfs/data/current/VERSION中的clusterID替换掉

完成

重新启动start-all.sh

正常启动

4000