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https://issues.apache.org/jira/browse/HADOOP-12107?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14594570#comment-14594570
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Hadoop QA commented on HADOOP-12107:
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| (x) *{color:red}-1 overall{color}* |
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|| Vote || Subsystem || Runtime || Comment ||
| {color:blue}0{color} | pre-patch | 16m 26s | Pre-patch trunk compilation is
healthy. |
| {color:green}+1{color} | @author | 0m 0s | The patch does not contain any
@author tags. |
| {color:red}-1{color} | tests included | 0m 0s | 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{color} | javac | 7m 29s | There were no new javac warning
messages. |
| {color:green}+1{color} | javadoc | 9m 39s | There were no new javadoc
warning messages. |
| {color:green}+1{color} | release audit | 0m 22s | The applied patch does
not increase the total number of release audit warnings. |
| {color:red}-1{color} | checkstyle | 1m 4s | The applied patch generated 1
new checkstyle issues (total was 142, now 140). |
| {color:green}+1{color} | whitespace | 0m 0s | The patch has no lines that
end in whitespace. |
| {color:green}+1{color} | install | 1m 34s | mvn install still works. |
| {color:green}+1{color} | eclipse:eclipse | 0m 34s | The patch built with
eclipse:eclipse. |
| {color:red}-1{color} | findbugs | 1m 56s | The patch appears to introduce 1
new Findbugs (version 3.0.0) warnings. |
| {color:green}+1{color} | common tests | 21m 55s | Tests passed in
hadoop-common. |
| | | 61m 3s | |
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|| Reason || Tests ||
| FindBugs | module:hadoop-common |
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|| Subsystem || Report/Notes ||
| Patch URL |
http://issues.apache.org/jira/secure/attachment/12740755/HADOOP-12107.001.patch
|
| Optional Tests | javadoc javac unit findbugs checkstyle |
| git revision | trunk / 20c03c9 |
| checkstyle |
https://builds.apache.org/job/PreCommit-HADOOP-Build/6997/artifact/patchprocess/diffcheckstylehadoop-common.txt
|
| Findbugs warnings |
https://builds.apache.org/job/PreCommit-HADOOP-Build/6997/artifact/patchprocess/newPatchFindbugsWarningshadoop-common.html
|
| hadoop-common test log |
https://builds.apache.org/job/PreCommit-HADOOP-Build/6997/artifact/patchprocess/testrun_hadoop-common.txt
|
| Test Results |
https://builds.apache.org/job/PreCommit-HADOOP-Build/6997/testReport/ |
| Java | 1.7.0_55 |
| uname | Linux asf909.gq1.ygridcore.net 3.13.0-36-lowlatency #63-Ubuntu SMP
PREEMPT Wed Sep 3 21:56:12 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux |
| Console output |
https://builds.apache.org/job/PreCommit-HADOOP-Build/6997/console |
This message was automatically generated.
> long running apps may have a huge number of StatisticsData instances under
> FileSystem
> -------------------------------------------------------------------------------------
>
> Key: HADOOP-12107
> URL: https://issues.apache.org/jira/browse/HADOOP-12107
> Project: Hadoop Common
> Issue Type: Bug
> Components: fs
> Affects Versions: 2.7.0
> Reporter: Sangjin Lee
> Assignee: Sangjin Lee
> Priority: Minor
> Attachments: HADOOP-12107.001.patch
>
>
> We observed with some of our apps (non-mapreduce apps that use filesystems)
> that they end up accumulating a huge memory footprint coming from
> {{FileSystem$Statistics$StatisticsData}} (in the {{allData}} list of
> {{Statistics}}).
> Although the thread reference from {{StatisticsData}} is a weak reference,
> and thus can get cleared once a thread goes away, the actual
> {{StatisticsData}} instances in the list won't get cleared until any of these
> following methods is called on {{Statistics}}:
> - {{getBytesRead()}}
> - {{getBytesWritten()}}
> - {{getReadOps()}}
> - {{getLargeReadOps()}}
> - {{getWriteOps()}}
> - {{toString()}}
> It is quite possible to have an application that interacts with a filesystem
> but does not call any of these methods on the {{Statistics}}. If such an
> application runs for a long time and has a large amount of thread churn, the
> memory footprint will grow significantly.
> The current workaround is either to limit the thread churn or to invoke these
> operations occasionally to pare down the memory. However, this is still a
> deficiency with {{FileSystem$Statistics}} itself in that the memory is
> controlled only as a side effect of those operations.
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