Hello, Running “hdfs dfsadmin -rollingUpgrade finalize” finalized the upgrade. This is a terminal state for the upgrade process, so afterwards, it is no longer possible to run “hdfs dfsadmin -rollingUpgrade downgrade”.
Rolling upgrade supports upgrading individual daemons independent of other daemons (e.g. just the DataNodes). If you want to proceed with upgrading your 2.5.0 DataNodes to 2.7.2, then I expect you can start a new rolling upgrade and proceed with the upgrade process on just the subset of DataNodes still running 2.5.0. --Chris Nauroth From: jinxing <[email protected]> Date: Tuesday, August 16, 2016 at 6:02 AM To: "[email protected]" <[email protected]> Subject: hfs downgrade from 2.7.2 to 2.5.0 Hello, it’s great to join this mailing list. Can I ask a question? Is it possible to downgrade cluster ? I have already upgrade my cluster’s namenodes(with one stand by for HA) and several datanodes from 2.5.0 folloing https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/HdfsRollingUpgrade.html#Downgrade_and_Rollback; I take following steps: 1. hdfs dfsadmin -rollingUpgrade prepare; 2. hdfs dfsadmin -rollingUpgrade query; 3. hdfs dfsadmin -shutdownDatanode <host:port> upgrade 4. restart and upgrade datanode; However, I terminated the upgrade by mistake with command "hfs dfsadmin -rollingUpgrade finalize" Currently, I have two 2.7.2 nematodes, and three 2.7.2 datanodes and 63 2.5.0 datanodes; Now I want to downgrade the nematodes and datanodes from 2.7.2 back to 2.5.0; But when I try to downgrade nematode and restart with “-rollingUpgrade downgrade”, namenode cannot get started, I get rolling exception: 2016-08-16 20:37:08,642 WARN org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Encountered exception loading fsimage org.apache.hadoop.hdfs.server.common.IncorrectVersionException: Unexpected version of storage directory /home/maintain/hadoop/data/hdfs-namenode. Reported: -63. Expecting = -57. at org.apache.hadoop.hdfs.server.common.StorageInfo.setLayoutVersion(StorageInfo.java:178) at org.apache.hadoop.hdfs.server.common.StorageInfo.setFieldsFromProperties(StorageInfo.java:131) at org.apache.hadoop.hdfs.server.namenode.NNStorage.setFieldsFromProperties(NNStorage.java:608) at org.apache.hadoop.hdfs.server.common.StorageInfo.readProperties(StorageInfo.java:228) at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverStorageDirs(FSImage.java:323) at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:202) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:955) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:700) at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:529) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:585) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:751) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:735) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1407) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1473) 2016-08-16 20:37:08,645 INFO org.mortbay.log: Stopped HttpServer2$SelectChannelConnectorWithSafeStartup@dx-pipe-sata61-pm:50070 2016-08-16 20:37:08,745 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Stopping NameNode metrics system... 2016-08-16 20:37:08,746 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system stopped. 2016-08-16 20:37:08,746 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system shutdown complete. 2016-08-16 20:37:08,746 FATAL org.apache.hadoop.hdfs.server.namenode.NameNode: Exception in namenode join org.apache.hadoop.hdfs.server.common.IncorrectVersionException: Unexpected version of storage directory /home/maintain/hadoop/data/hdfs-namenode. Reported: -63. Expecting = -57. at org.apache.hadoop.hdfs.server.common.StorageInfo.setLayoutVersion(StorageInfo.java:178) at org.apache.hadoop.hdfs.server.common.StorageInfo.setFieldsFromProperties(StorageInfo.java:131) at org.apache.hadoop.hdfs.server.namenode.NNStorage.setFieldsFromProperties(NNStorage.java:608) at org.apache.hadoop.hdfs.server.common.StorageInfo.readProperties(StorageInfo.java:228) at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverStorageDirs(FSImage.java:323) at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:202) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:955) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:700) at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:529) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:585) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:751) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:735) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1407) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1473) It’s great if someone can help?
