For 8.a, please refer to http://hadoop.apache.org/docs/r2.3.0/hadoop-project-dist/hadoop-hdfs/HdfsUserGuide.html#Upgrade_and_Rollback
Cheers On Jul 9, 2014, at 4:42 AM, "Kiran Kumar.M.R" <[email protected]> wrote: > Hi, > We are proposing upgrade solution to one of our customers. > > Current Version: Hadoop 2.0.1+Hbase 0.94.11+ ZK > Upgrade Version: Hadoop 2.3+HBase 0.98 +ZK > > Current Cluster Setup: with 50+ nodes storing 300TB of HBase data > All components are installed under $HADOOP_V1. > NN, DN and ZK directories are external. > > Main requirement is that customer wants to rollback to old version in case of > any failures during the upgrade. > HDFS provides rollback option. HBase has no rollback option. To overcome > this, I am thinking of running HBase upgrade under hdfs -upgrade step. > > Detailed steps are given below: > > 1. Shutdown $HADOOP_V1 cluster > > 2. Take backup of $NN_DR and $ZK_DIR > > 3. Install new version (Hadoop 2.3+HBase 0.98 +ZK) under new directory > on same nodes i.e $HADOOP_V2 > > 4. Configure it to use existing folders $NN_DIR, $DN_DIR, $ZK_DIR > > 5. Start Zk > > 6. Start hdfs with -upgrade option > > 7. Start hbase upgrade tool "$ bin/hbase upgrade -execute" > > 8. In case of any failure do rollback > > a. HDFS rollback > > b. Stop ZK and recover old ZK data backup to ZK_DIR > > c. Start old version $HA DOOP_V1 (HBase 0.94 should work as HDFS > rollback should revert namespace and other changes done by meta data tool) > > 9. If HBase upgrade is fine, finalize upgrade > > a. HDFS finalizeUpgrade > > b. Delete old version > > I am mainly concerned about step 8, is this rollback expected to work? > Are there any better alternatives to do HBase rollback. > > Regards, > Kiran > > > >
