[HDFS-dev] [jira] Created: (HDFS-1125) Removing a datanode (failed or decommissioned) should not require a namenode restart

Removing a datanode (failed or decommissioned) should not require a namenode restart
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Key: HDFS-1125
URL: https://issues.apache.org/jira/browse/HDFS-1125
Project: Hadoop HDFS
Issue Type: Bug
Components: name-node
Reporter: Alex Loddengaard
Priority: Minor


I've heard of several Hadoop users using dfsadmin -report to monitor the number of dead nodes, and alert if that number is not 0. This mechanism tends to work pretty well, except when a node is decommissioned or fails, because then the namenode requires a restart for said node to be entirely removed from HDFS. More details here:

http://markmail.org/search/?q=decommissioned%20node%20showing%20up%20ad%20dead%20node%20in%20web%20based%09interface%20to%20namenode#query:decommissioned%20node%20showing%20up%20ad%20dead%20node%20in%20web%20based%09interface%20to%20namenode+page:1+mid:7gwqwdkobgfuszb4+state:results

Removal from the exclude file and a refresh should get rid of the dead node.