[ https://issues.apache.org/jira/browse/HDFS-6735?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14227945#comment-14227945 ]
Hadoop QA commented on HDFS-6735: --------------------------------- {color:red}-1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12684091/HDFS-6735-v6.txt against trunk revision c1f2bb2. {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:red}-1 tests included{color}. The patch doesn't appear to include any new or modified tests. Please justify why no new tests are needed for this patch. Also please list what manual steps were performed to verify this patch. {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:red}-1 findbugs{color}. The patch appears to introduce 1 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/8864//testReport/ Findbugs warnings: https://builds.apache.org/job/PreCommit-HDFS-Build/8864//artifact/patchprocess/newPatchFindbugsWarningshadoop-hdfs.html Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/8864//console This message is automatically generated. > A minor optimization to avoid pread() be blocked by read() inside the same > DFSInputStream > ----------------------------------------------------------------------------------------- > > Key: HDFS-6735 > URL: https://issues.apache.org/jira/browse/HDFS-6735 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client > Affects Versions: 3.0.0 > Reporter: Liang Xie > Assignee: Lars Hofhansl > Attachments: HDFS-6735-v2.txt, HDFS-6735-v3.txt, HDFS-6735-v4.txt, > HDFS-6735-v5.txt, HDFS-6735-v6.txt, HDFS-6735-v7.txt, HDFS-6735.txt > > > In current DFSInputStream impl, there're a couple of coarser-grained locks in > read/pread path, and it has became a HBase read latency pain point so far. In > HDFS-6698, i made a minor patch against the first encourtered lock, around > getFileLength, in deed, after reading code and testing, it shows still other > locks we could improve. > In this jira, i'll make a patch against other locks, and a simple test case > to show the issue and the improved result. > This is important for HBase application, since in current HFile read path, we > issue all read()/pread() requests in the same DFSInputStream for one HFile. > (Multi streams solution is another story i had a plan to do, but probably > will take more time than i expected) -- This message was sent by Atlassian JIRA (v6.3.4#6332)