Hadoop叢集改名導緻無法啟動DataNode

之前叢集能夠啟動各個節點的。

因為最近叢集改名了，啟動NameNode可以的。

啟動DataNode沒有任何提示。

進入hadoop logs目錄查找hadoop-root-datanode-bd-cluster1.log檔案發現下面的錯誤。

錯誤關鍵資訊： org.apache.hadoop.hdfs.server.common.Storage: Failed to add storage directory [DISK]file:/tmp/hadoop-root/dfs/data

java.io.IOException: Incompatible clusterIDs in /tmp/hadoop-root/dfs/data: namenode clusterID = CID-17d9d128-d0f2-4b73-9460-0074536fa7a7; datanode clusterID = CID-29c3283b-0f02-4814-ae01-50065e15c004

2021-05-15 15:34:23,573 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Acknowledging ACTIVE Namenode during handshakeBlock pool (Datanode Uuid unassigned) service to /10.231.33.101:9000

2021-05-15 15:34:23,582 INFO org.apache.hadoop.hdfs.server.common.Storage: Using 1 threads to upgrade data directories (dfs.datanode.parallel.volumes.load.threads.num=1, dataDirs=1)

2021-05-15 15:34:23,597 INFO org.apache.hadoop.hdfs.server.common.Storage: Lock on /tmp/hadoop-root/dfs/data/in_use.lock acquired by nodename 5526@bd-cluster1

2021-05-15 15:34:23,600 WARN org.apache.hadoop.hdfs.server.common.Storage: Failed to add storage directory [DISK]file:/tmp/hadoop-root/dfs/data

at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:744)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.loadStorageDirectory(DataStorage.java:294)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.loadDataStorage(DataStorage.java:407)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.addStorageLocations(DataStorage.java:387)

at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:559)

at org.apache.hadoop.hdfs.server.datanode.DataNode.initStorage(DataNode.java:1743)

at org.apache.hadoop.hdfs.server.datanode.DataNode.initBlockPool(DataNode.java:1679)

at org.apache.hadoop.hdfs.server.datanode.BPOfferService.verifyAndSetNamespaceInfo(BPOfferService.java:390)

at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.connectToNNAndHandshake(BPServiceActor.java:282)

at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:824)

at java.lang.Thread.run(Thread.java:748)

2021-05-15 15:34:23,602 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool (Datanode Uuid f4005613-8a0d-4177-a59a-5a999f41ccd6) service to /10.231.33.101:9000. Exiting.

java.io.IOException: All specified directories have failed to load.

at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:560)

2021-05-15 15:34:23,603 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Ending block pool service for: Block pool (Datanode Uuid f4005613-8a0d-4177-a59a-5a999f41ccd6) service to /10.231.33.101:9000

分析

上面的錯誤就是因為本地的DataNode之前存儲過舊叢集資料，寫新資料的時候發現版本不一樣。

直接删除舊的DataNode的資料目錄, 預設為：/tmp/hadoop-root/dfs/data.

重新運作：hdfs --daemon start datanode

啟動成功了：datanode連接配接成功。

好了，如果有多個DataNode必須重複删除所有DataNode的資料檔案，再運作上述指令。

總結

根本原因：不同叢集資料問題校驗問題，錯誤為Incompatible clusterIDs錯誤