Dear Wiki user, You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.
The "Hbase/MigrationToNewCluster" page has been changed by NatHarward. The comment on this change is: Fixing numbering. http://wiki.apache.org/hadoop/Hbase/MigrationToNewCluster?action=diff&rev1=2&rev2=3 -------------------------------------------------- The steps: - # Get existing Hbase into a stable state + I. Get existing Hbase into a stable state - # Disable access to the existing Hbase, so that no data is changing (optionally disabling your tables just to be sure) + i. Disable access to the existing Hbase, so that no data is changing (optionally disabling your tables just to be sure) - # Major compact all tables + i. Major compact all tables - # Flush all tables + i. Flush all tables - # Shut down Hbase + i. Shut down Hbase - # Get existing HDFS into a stable state + I. Get existing HDFS into a stable state - # Disable any other HDFS access besides Hbase which should now be shut down + i. Disable any other HDFS access besides Hbase which should now be shut down - # Enter HDFS safe-mode + i. Enter HDFS safe-mode - # Run ''fsck'' and verify that everything is ok + i. Run ''fsck'' and verify that everything is ok - # Push Hbase data from the old cluster to the new one + I. Push Hbase data from the old cluster to the new one - # Use the ''distcp'' command to copy your Hbase root directory to the new cluster (this command uses Map/Reduce, so it should be available where you run this command) + i. Use the ''distcp'' command to copy your Hbase root directory to the new cluster (this command uses Map/Reduce, so it should be available where you run this command) - # ''Note: when I tried copying the root of the entire HDFS tree I got a NPE, but pushing a top-level directory worked fine'' + i. ''Note: when I tried copying the root of the entire HDFS tree I got a NPE, but pushing a top-level directory worked fine'' - # Verify data in the new HDFS cluster + I. Verify data in the new HDFS cluster - # I did a spot-check of file sizes and directories to my satisfaction -- depending on how important your data is you may want some kind of checksumming crawler for verification + i. I did a spot-check of file sizes and directories to my satisfaction -- depending on how important your data is you may want some kind of checksumming crawler for verification - # Run ''fsck'' to make sure HDFS is happy and does not think anything is wrong + i. Run ''fsck'' to make sure HDFS is happy and does not think anything is wrong - # Fire up Hbase in the new cluster + I. Fire up Hbase in the new cluster - # Make sure your configuration points to the ''new'' Hbase root directory in the new cluster + i. Make sure your configuration points to the ''new'' Hbase root directory in the new cluster - # Verify Hbase connectivity, and again to your satisfaction verify the data accessible through your new Hbase instance + I. Verify Hbase connectivity, and again to your satisfaction verify the data accessible through your new Hbase instance - # Finito! + I. Finito! I specifically did not attempt to migrate any Zookeeper data, and found that I did not need to -- I did not encounter any problems in skipping this but your mileage may vary.
