[ https://issues.apache.org/jira/browse/HDFS-1295?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Suresh Srinivas updated HDFS-1295: ---------------------------------- Resolution: Fixed Hadoop Flags: [Reviewed] Status: Resolved (was: Patch Available) I committed the patch. Thank you Matt. > Improve namenode restart times by short-circuiting the first block reports > from datanodes > ----------------------------------------------------------------------------------------- > > Key: HDFS-1295 > URL: https://issues.apache.org/jira/browse/HDFS-1295 > Project: Hadoop HDFS > Issue Type: Improvement > Components: name-node > Affects Versions: 0.22.0 > Reporter: dhruba borthakur > Assignee: Matt Foley > Fix For: 0.23.0 > > Attachments: IBR_shortcut_v2a.patch, IBR_shortcut_v3atrunk.patch, > IBR_shortcut_v4atrunk.patch, IBR_shortcut_v4atrunk.patch, > IBR_shortcut_v4atrunk.patch, IBR_shortcut_v6atrunk.patch, > IBR_shortcut_v7atrunk.patch, shortCircuitBlockReport_1.txt > > > The namenode restart is dominated by the performance of processing block > reports. On a 2000 node cluster with 90 million blocks, block report > processing takes 30 to 40 minutes. The namenode "diffs" the contents of the > incoming block report with the contents of the blocks map, and then applies > these diffs to the blocksMap, but in reality there is no need to compute the > "diff" because this is the first block report from the datanode. > This code change improves block report processing time by 300%. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira