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Kihwal Lee commented on HDFS-14563: ----------------------------------- Maintenance mode is different from other admin state. It has expiration. The command line tool should be able to specify that (my example patch includes it). > Enhance interface about recommissioning/decommissioning > ------------------------------------------------------- > > Key: HDFS-14563 > URL: https://issues.apache.org/jira/browse/HDFS-14563 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client, namenode > Reporter: He Xiaoqiao > Assignee: He Xiaoqiao > Priority: Major > Attachments: HDFS-14563.001.patch, HDFS-14563.002.patch, mt_mode-2.txt > > > In current implementation, if we need to decommissioning or recommissioning > one datanode, the only way is add the datanode to include or exclude file > under namenode configuration path then execute command `bin/hadoop dfsadmin > -refreshNodes` and trigger namenode to reload include/exclude and start to > recommissioning or decommissioning datanode. > The shortcomings of this approach is that: > a. namenode reload include/exclude configuration file from devices, if I/O > load is high, handler may be blocked. > b. namenode has to process every datnodes in include and exclude > configurations, if there are many datanodes (very common for large cluster) > pending to process, namenode will be hung for hundred seconds to wait > recommision/decommision finish at the worst since holding write lock. > I think we should expose one lightweight interface to support recommissioning > or decommissioning single datanode, thus we can operate datanode using > dfsadmin more smooth. -- This message was sent by Atlassian JIRA (v7.6.14#76016) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org