[jira] [Reopened] (HDFS-11187) Optimize disk access for last partial chunk checksum of Finalized replica
[ https://issues.apache.org/jira/browse/HDFS-11187?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Gabor Bota reopened HDFS-11187: --- Reopened to provide patch for branch-2.7 > Optimize disk access for last partial chunk checksum of Finalized replica > - > > Key: HDFS-11187 > URL: https://issues.apache.org/jira/browse/HDFS-11187 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode >Reporter: Wei-Chiu Chuang >Assignee: Gabor Bota >Priority: Major > Fix For: 3.1.0, 2.10.0, 2.9.1, 2.8.4, 3.0.2 > > Attachments: HDFS-11187-branch-2.001.patch, > HDFS-11187-branch-2.002.patch, HDFS-11187-branch-2.003.patch, > HDFS-11187-branch-2.004.patch, HDFS-11187-branch-2.7.001.patch, > HDFS-11187.001.patch, HDFS-11187.002.patch, HDFS-11187.003.patch, > HDFS-11187.004.patch, HDFS-11187.005.patch > > > The patch at HDFS-11160 ensures BlockSender reads the correct version of > metafile when there are concurrent writers. > However, the implementation is not optimal, because it must always read the > last partial chunk checksum from disk while holding FsDatasetImpl lock for > every reader. It is possible to optimize this by keeping an up-to-date > version of last partial checksum in-memory and reduce disk access. > I am separating the optimization into a new jira, because maintaining the > state of in-memory checksum requires a lot more work. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
[jira] [Reopened] (HDFS-11187) Optimize disk access for last partial chunk checksum of Finalized replica
[ https://issues.apache.org/jira/browse/HDFS-11187?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Gabor Bota reopened HDFS-11187: --- Assignee: Gabor Bota (was: Wei-Chiu Chuang) Reopening this to add the change to branch-2 > Optimize disk access for last partial chunk checksum of Finalized replica > - > > Key: HDFS-11187 > URL: https://issues.apache.org/jira/browse/HDFS-11187 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode >Reporter: Wei-Chiu Chuang >Assignee: Gabor Bota >Priority: Major > Fix For: 3.1.0, 3.0.2 > > Attachments: HDFS-11187.001.patch, HDFS-11187.002.patch, > HDFS-11187.003.patch, HDFS-11187.004.patch, HDFS-11187.005.patch > > > The patch at HDFS-11160 ensures BlockSender reads the correct version of > metafile when there are concurrent writers. > However, the implementation is not optimal, because it must always read the > last partial chunk checksum from disk while holding FsDatasetImpl lock for > every reader. It is possible to optimize this by keeping an up-to-date > version of last partial checksum in-memory and reduce disk access. > I am separating the optimization into a new jira, because maintaining the > state of in-memory checksum requires a lot more work. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
