[ https://issues.apache.org/jira/browse/HDFS-5046?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Harsh J resolved HDFS-5046. --------------------------- Resolution: Not A Problem bq. a). decommission progress hangs and the status always be 'Waiting DataNode status: Decommissioned'. But, if I execute 'hadoop dfs -setrep -R 2 /', the decommission continues and will be completed finally. The step (a) points to your problem and solution both. You have files being created with repl=3 on a 2 DN cluster which will prevent decommission. This is not a bug. > Hang when add/remove a datanode into/from a 2 datanode cluster > -------------------------------------------------------------- > > Key: HDFS-5046 > URL: https://issues.apache.org/jira/browse/HDFS-5046 > Project: Hadoop HDFS > Issue Type: Bug > Components: datanode > Affects Versions: 1.1.1 > Environment: Red Hat Enterprise Linux Server release 5.3, 64 bit > Reporter: sam liu > > 1. Install a Hadoop 1.1.1 cluster, with 2 datanodes: dn1 and dn2. And, in > hdfs-site.xml, set the 'dfs.replication' to 2 > 2. Add node dn3 into the cluster as a new datanode, and did not change the > 'dfs.replication' value in hdfs-site.xml and keep it as 2 > note: step 2 passed > 3. Decommission dn3 from the cluster > Expected result: dn3 could be decommissioned successfully > Actual result: > a). decommission progress hangs and the status always be 'Waiting DataNode > status: Decommissioned'. But, if I execute 'hadoop dfs -setrep -R 2 /', the > decommission continues and will be completed finally. > b). However, if the initial cluster includes >= 3 datanodes, this issue won't > be encountered when add/remove another datanode. For example, if I setup a > cluster with 3 datanodes, and then I can successfully add the 4th datanode > into it, and then also can successfully remove the 4th datanode from the > cluster. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira