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Hadoop QA commented on HADOOP-16833: ------------------------------------ | (/) *{color:green}+1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m 42s{color} | {color:blue} Docker mode activated. {color} | || || || || {color:brown} Prechecks {color} || | {color:green}+1{color} | {color:green} @author {color} | {color:green} 0m 0s{color} | {color:green} The patch does not contain any @author tags. {color} | | {color:green}+1{color} | {color:green} test4tests {color} | {color:green} 0m 0s{color} | {color:green} The patch appears to include 2 new or modified test files. {color} | || || || || {color:brown} trunk Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 20m 19s{color} | {color:green} trunk passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 16m 12s{color} | {color:green} trunk passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 41s{color} | {color:green} trunk passed {color} | | {color:green}+1{color} | {color:green} mvnsite {color} | {color:green} 1m 17s{color} | {color:green} trunk passed {color} | | {color:green}+1{color} | {color:green} shadedclient {color} | {color:green} 14m 53s{color} | {color:green} branch has no errors when building and testing our client artifacts. {color} | | {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 1m 42s{color} | {color:green} trunk passed {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 21s{color} | {color:green} trunk passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 0m 46s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 15m 18s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 15m 18s{color} | {color:green} the patch passed {color} | | {color:orange}-0{color} | {color:orange} checkstyle {color} | {color:orange} 0m 43s{color} | {color:orange} hadoop-common-project/hadoop-common: The patch generated 1 new + 1 unchanged - 0 fixed = 2 total (was 1) {color} | | {color:green}+1{color} | {color:green} mvnsite {color} | {color:green} 1m 12s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} whitespace {color} | {color:green} 0m 0s{color} | {color:green} The patch has no whitespace issues. {color} | | {color:green}+1{color} | {color:green} shadedclient {color} | {color:green} 12m 50s{color} | {color:green} patch has no errors when building and testing our client artifacts. {color} | | {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 1m 47s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 19s{color} | {color:green} the patch passed {color} | || || || || {color:brown} Other Tests {color} || | {color:green}+1{color} | {color:green} unit {color} | {color:green} 9m 6s{color} | {color:green} hadoop-common in the patch passed. {color} | | {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m 43s{color} | {color:green} The patch does not generate ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black}100m 50s{color} | {color:black} {color} | \\ \\ || Subsystem || Report/Notes || | Docker | Client=19.03.5 Server=19.03.5 Image:yetus/hadoop:c44943d1fc3 | | JIRA Issue | HADOOP-16833 | | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12992679/HADOOP-16833.005.patch | | Optional Tests | dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient findbugs checkstyle | | uname | Linux 4ef44712344a 4.15.0-74-generic #84-Ubuntu SMP Thu Dec 19 08:06:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux | | Build tool | maven | | Personality | /testptch/patchprocess/precommit/personality/provided.sh | | git revision | trunk / ce7b8b5 | | maven | version: Apache Maven 3.3.9 | | Default Java | 1.8.0_242 | | findbugs | v3.1.0-RC1 | | checkstyle | https://builds.apache.org/job/PreCommit-HADOOP-Build/16755/artifact/out/diff-checkstyle-hadoop-common-project_hadoop-common.txt | | Test Results | https://builds.apache.org/job/PreCommit-HADOOP-Build/16755/testReport/ | | Max. process+thread count | 1500 (vs. ulimit of 5500) | | modules | C: hadoop-common-project/hadoop-common U: hadoop-common-project/hadoop-common | | Console output | https://builds.apache.org/job/PreCommit-HADOOP-Build/16755/console | | Powered by | Apache Yetus 0.8.0 http://yetus.apache.org | This message was automatically generated. > InstrumentedLock should log lock queue time > ------------------------------------------- > > Key: HADOOP-16833 > URL: https://issues.apache.org/jira/browse/HADOOP-16833 > Project: Hadoop Common > Issue Type: Improvement > Components: util > Affects Versions: 3.3.0 > Reporter: Stephen O'Donnell > Assignee: Stephen O'Donnell > Priority: Major > Attachments: HADOOP-16833.001.patch, HADOOP-16833.002.patch, > HADOOP-16833.003.patch, HADOOP-16833.004.patch, HADOOP-16833.005.patch > > > Within the Datanode, we often see contention around the FsDatasetImpl lock. > This can be for various reasons, eg the DN is under IO load, and other bugs, > eg HDFS-15131. > When DN slow downs happen, it is very difficult to debug what is causing it, > as there are few messages in the logs which indicate what is happening. > In my experience, the presence of this log is informative: > {code} > 2019-11-27 09:00:49,678 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: > Took 21540ms to process 1 commands from NN > {code} > This comes from the datanode heartbeat thread, and it is logged when the > commands returned from the heartbeat cannot be enqueued, and usually this is > because the thread cannot get the FsDatasetImpl lock due to contention with > other slow threads. > HDFS-14997 moved the command processing to an async thread, and hence this > useful message will disappear. > InstrumentedLock introduced a feature to the datanode, where it will log a > stack trace if any thread holds the lock for over 300ms. However this will > not catch a scenario where 10 threads each hold a lock for 200ms, leading to > the next in the queue having waited over 2 seconds. > I believe it would be useful to extend InstrumentedLock to log if a thread > has to wait for over some threshold. That way, we could be able to catch > scenarios like the heartbeat thread shows us, but in a much more obvious way, > provided lock contention is involved. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org