[jira] [Updated] (HDFS-8710) Always read DU value from the cached dfsUsed file on datanode startup
[ https://issues.apache.org/jira/browse/HDFS-8710?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Allen Wittenauer updated HDFS-8710: --- Resolution: Won't Fix Status: Resolved (was: Patch Available) Always read DU value from the cached dfsUsed file on datanode startup --- Key: HDFS-8710 URL: https://issues.apache.org/jira/browse/HDFS-8710 Project: Hadoop HDFS Issue Type: Improvement Reporter: Xinwei Qin Assignee: Xinwei Qin Attachments: HDFS-8710.001.patch Currently, DataNode will cache DU value in dfsUsed file termly. When DataNode starts or restarts, it will read in the cached DU value from dfsUsed file if the value is less than 600 seconds old, otherwise, it will run DU command, which is a very time-consuming operation(may up to dozens of minutes) when DataNode has huge number of blocks. Since slight imprecision of dfsUsed is not critical, and the DU value will be updated every 600 seconds (the default DU interval) after DataNode started, we can always read DU value from the cached file (Regardless of whether this value is less than 600 seconds old or not) and skip DU operation on DataNode startup to significantly shorten the startup time. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
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[jira] [Updated] (HDFS-8710) Always read DU value from the cached dfsUsed file on datanode startup
[ https://issues.apache.org/jira/browse/HDFS-8710?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Xinwei Qin updated HDFS-8710: -- Attachment: HDFS-8710.001.patch Attached the patch to review. Always read DU value from the cached dfsUsed file on datanode startup --- Key: HDFS-8710 URL: https://issues.apache.org/jira/browse/HDFS-8710 Project: Hadoop HDFS Issue Type: Improvement Reporter: Xinwei Qin Assignee: Xinwei Qin Attachments: HDFS-8710.001.patch Currently, DataNode will cache DU value in dfsUsed file termly. When DataNode starts or restarts, it will read in the cached DU value from dfsUsed file if the value is less than 600 seconds old, otherwise, it will run DU command, which is a very time-consuming operation(may up to dozens of minutes) when DataNode has huge number of blocks. Since slight imprecision of dfsUsed is not critical, and the DU value will be updated every 600 seconds (the default DU interval) after DataNode started, we can always read DU value from the cached file (Regardless of whether this value is less than 600 seconds old or not) and skip DU operation on DataNode startup to significantly shorten the startup time. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-8710) Always read DU value from the cached dfsUsed file on datanode startup
[ https://issues.apache.org/jira/browse/HDFS-8710?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Xinwei Qin updated HDFS-8710: -- Status: Patch Available (was: Open) Always read DU value from the cached dfsUsed file on datanode startup --- Key: HDFS-8710 URL: https://issues.apache.org/jira/browse/HDFS-8710 Project: Hadoop HDFS Issue Type: Improvement Reporter: Xinwei Qin Assignee: Xinwei Qin Attachments: HDFS-8710.001.patch Currently, DataNode will cache DU value in dfsUsed file termly. When DataNode starts or restarts, it will read in the cached DU value from dfsUsed file if the value is less than 600 seconds old, otherwise, it will run DU command, which is a very time-consuming operation(may up to dozens of minutes) when DataNode has huge number of blocks. Since slight imprecision of dfsUsed is not critical, and the DU value will be updated every 600 seconds (the default DU interval) after DataNode started, we can always read DU value from the cached file (Regardless of whether this value is less than 600 seconds old or not) and skip DU operation on DataNode startup to significantly shorten the startup time. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
