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https://issues.apache.org/jira/browse/MAPREDUCE-6957?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16164825#comment-16164825
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Hadoop QA commented on MAPREDUCE-6957:
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| (/) *{color:green}+1 overall{color}* |
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|| Vote || Subsystem || Runtime || Comment ||
| {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 20m
27s{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} 15m
48s{color} | {color:green} trunk passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
30s{color} | {color:green} trunk passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m
20s{color} | {color:green} trunk passed {color} |
| {color:green}+1{color} | {color:green} mvnsite {color} | {color:green} 0m
32s{color} | {color:green} trunk passed {color} |
| {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 0m
55s{color} | {color:green} trunk passed {color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
23s{color} | {color:green} trunk passed {color} |
|| || || || {color:brown} Patch Compile Tests {color} ||
| {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 0m
26s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} compile {color} | {color:green} 0m
26s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javac {color} | {color:green} 0m
26s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m
18s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} mvnsite {color} | {color:green} 0m
29s{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} findbugs {color} | {color:green} 1m
5s{color} | {color:green} the patch passed {color} |
| {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m
21s{color} | {color:green} the patch passed {color} |
|| || || || {color:brown} Other Tests {color} ||
| {color:green}+1{color} | {color:green} unit {color} | {color:green} 3m
0s{color} | {color:green} hadoop-mapreduce-client-core in the patch passed.
{color} |
| {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m
14s{color} | {color:green} The patch does not generate ASF License warnings.
{color} |
| {color:black}{color} | {color:black} {color} | {color:black} 45m 57s{color} |
{color:black} {color} |
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|| Subsystem || Report/Notes ||
| Docker | Image:yetus/hadoop:71bbb86 |
| JIRA Issue | MAPREDUCE-6957 |
| JIRA Patch URL |
https://issues.apache.org/jira/secure/attachment/12886881/MAPREDUCE-6957.003.patch
|
| Optional Tests | asflicense compile javac javadoc mvninstall mvnsite
unit findbugs checkstyle |
| uname | Linux 3b92538772e6 4.4.0-43-generic #63-Ubuntu SMP Wed Oct 12
13:48:03 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux |
| Build tool | maven |
| Personality | /testptch/hadoop/patchprocess/precommit/personality/provided.sh
|
| git revision | trunk / fa6cc43 |
| Default Java | 1.8.0_144 |
| findbugs | v3.1.0-RC1 |
| Test Results |
https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/7132/testReport/ |
| modules | C:
hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core
U:
hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core |
| Console output |
https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/7132/console |
| Powered by | Apache Yetus 0.5.0 http://yetus.apache.org |
This message was automatically generated.
> shuffle hangs after a node manager connection timeout
> -----------------------------------------------------
>
> Key: MAPREDUCE-6957
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-6957
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: mrv2
> Reporter: Jooseong Kim
> Assignee: Jooseong Kim
> Attachments: MAPREDUCE-6957.001.patch, MAPREDUCE-6957.002.patch,
> MAPREDUCE-6957.003.patch
>
>
> After a connection failure from the reducer to the node manager, shuffles
> started to hang with the following message:
> {code}
> org.apache.hadoop.mapreduce.task.reduce.Fetcher: fetcher#1 - MergeManager
> returned status WAIT ...
> {code}
> There are two problems that leads to the hang.
> Problem 1.
> When a reducer has an issue connecting to the node manager, copyFromHost may
> call putBackKnownMapOutput on the same task attempt multiple times.
> There are two call sites of putBackKnownMapOutput in copyFromHost since
> MAPREDUCE-6303:
> 1. In the finally block of copyFromHost
> 2. In the catch block of openShuffleUrl.
> When openShuffleUrl fails to connect from the catch block in copyFromHost, it
> returns null.
> By the time openShuffleUrl returns null, putBackKnownMapOutput would have
> been called already for all remaining map outputs.
> However, the finally block calls putBackKnownMapOutput one more time on the
> map outputs.
> Problem 2. Problem 1 causes a leak in MergeManager.
> The problem occurs when multiple fetchers get the same set of map attempt
> outputs to fetch.
> Different fetchers reserves memory from MergeManager in Fetcher.copyMapOutput
> for the same map outputs.
> When the fetch succeeds, only the first map output gets committed through
> ShuffleSchedulerImpl.copySucceeded -> InMemoryMapOutput.commit, because
> commit() is gated by !finishedMaps[mapIndex].
> This may lead to a condition where usedMemory > memoryLimit, while
> commitMemory < mergeThreshold.
> This gets the MergeManager into a deadlock where a merge is never triggered
> while MergeManager cannot reserve additional space for map outputs.
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