[ https://issues.apache.org/jira/browse/HDFS-6871?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14103743#comment-14103743 ]
Hadoop QA commented on HDFS-6871: --------------------------------- {color:green}+1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12663073/HDFS-6871.003.patch against trunk revision . {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 1 new or modified test files. {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:green}+1 javadoc{color}. There were no new javadoc warning messages. {color:green}+1 eclipse:eclipse{color}. The patch built with eclipse:eclipse. {color:green}+1 findbugs{color}. The patch does not introduce any new Findbugs (version 2.0.3) warnings. {color:green}+1 release audit{color}. The applied patch does not increase the total number of release audit warnings. {color:green}+1 core tests{color}. The patch passed unit tests in hadoop-hdfs-project/hadoop-hdfs. {color:green}+1 contrib tests{color}. The patch passed contrib unit tests. Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/7690//testReport/ Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/7690//console This message is automatically generated. > Improve NameNode performance when creating file > ------------------------------------------------- > > Key: HDFS-6871 > URL: https://issues.apache.org/jira/browse/HDFS-6871 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode, performance > Reporter: Yi Liu > Assignee: Yi Liu > Priority: Critical > Fix For: 2.6.0 > > Attachments: HDFS-6871.001.patch, HDFS-6871.002.patch, > HDFS-6871.003.patch > > > Creating file with overwrite flag will cause NN fall into flush edit logs and > block other requests if the file exists. > When we create a file with overwrite flag (default is true) in HDFS, NN will > remove original file if it exists. In FSNamesystem#startFileInternal, NN > already holds the write lock, it calls {{deleteInt}} if the file exists, > there is logSync in {{deleteInt}}. So in this case, logSync is under write > lock, it will heavily affect the NN performance. > We should ignore the force logSync in {{deleteInt}} in this case. -- This message was sent by Atlassian JIRA (v6.2#6252)