[jira] [Commented] (HDFS-9137) DeadLock between DataNode#refreshVolumes and BPOfferService#registrationSucceeded

["Hadoop QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HDFS-9137?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14942006#comment-14942006 ] 

Hadoop QA commented on HDFS-9137:
---------------------------------

\\
\\
| (x) *{color:red}-1 overall{color}* |
\\
\\
|| Vote || Subsystem || Runtime || Comment ||
| {color:blue}0{color} | pre-patch |  27m 14s | 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 |  12m 16s | There were no new javac warning messages. |
| {color:green}+1{color} | javadoc |  16m 22s | There were no new javadoc warning messages. |
| {color:red}-1{color} | release audit |   0m 20s | The applied patch generated 1 release audit warnings. |
| {color:red}-1{color} | checkstyle |   1m 55s | The applied patch generated  1 new checkstyle issues (total was 142, now 142). |
| {color:green}+1{color} | whitespace |   0m  0s | The patch has no lines that end in whitespace. |
| {color:green}+1{color} | install |   1m 43s | mvn install still works. |
| {color:green}+1{color} | eclipse:eclipse |   0m 35s | The patch built with eclipse:eclipse. |
| {color:green}+1{color} | findbugs |   2m 46s | The patch does not introduce any new Findbugs (version 3.0.0) warnings. |
| {color:green}+1{color} | native |   3m 36s | Pre-build of native portion |
| {color:red}-1{color} | hdfs tests | 185m 52s | Tests failed in hadoop-hdfs. |
| | | 252m 45s | |
\\
\\
|| Reason || Tests ||
| Failed unit tests | hadoop.hdfs.server.namenode.ha.TestEditLogTailer |
|   | hadoop.hdfs.server.namenode.TestFSNamesystem |
| Timed out tests | org.apache.hadoop.hdfs.server.namenode.ha.TestStandbyCheckpoints |
|   | org.apache.hadoop.hdfs.TestDFSStripedOutputStreamWithFailure000 |
\\
\\
|| Subsystem || Report/Notes ||
| Patch URL | http://issues.apache.org/jira/secure/attachment/12764836/HDFS-9137.00.patch |
| Optional Tests | javadoc javac unit findbugs checkstyle |
| git revision | trunk / fdf02d1 |
| Release Audit | https://builds.apache.org/job/PreCommit-HDFS-Build/12777/artifact/patchprocess/patchReleaseAuditProblems.txt |
| checkstyle |  https://builds.apache.org/job/PreCommit-HDFS-Build/12777/artifact/patchprocess/diffcheckstylehadoop-hdfs.txt |
| hadoop-hdfs test log | https://builds.apache.org/job/PreCommit-HDFS-Build/12777/artifact/patchprocess/testrun_hadoop-hdfs.txt |
| Test Results | https://builds.apache.org/job/PreCommit-HDFS-Build/12777/testReport/ |
| Java | 1.7.0_55 |
| uname | Linux asf907.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-HDFS-Build/12777/console |


This message was automatically generated.

> DeadLock between DataNode#refreshVolumes and BPOfferService#registrationSucceeded 
> ----------------------------------------------------------------------------------
>
>                 Key: HDFS-9137
>                 URL: https://issues.apache.org/jira/browse/HDFS-9137
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: datanode
>    Affects Versions: 3.0.0, 2.7.1
>            Reporter: Uma Maheswara Rao G
>            Assignee: Uma Maheswara Rao G
>         Attachments: HDFS-9137.00.patch
>
>
> I can see this code flows between DataNode#refreshVolumes and BPOfferService#registrationSucceeded could cause deadLock.
> In practice situation may be rare as user calling refreshVolumes at the time DN registration with NN. But seems like issue can happen.
>  Reason for deadLock:
>   1) refreshVolumes will be called with DN lock and after at the end it will also trigger Block report. In the Block report call, BPServiceActor#triggerBlockReport calls toString on bpos. Here it takes readLock on bpos.
>  DN lock then boos lock
> 2) BPOfferSetrvice#registrationSucceeded call is taking writeLock on bpos and  calling dn.bpRegistrationSucceeded which is again synchronized call on DN.
> bpos lock and then DN lock.
> So, this can clearly create dead lock.
> I think simple fix could be to move triggerBlockReport call outside out DN lock and I feel that call may not be really needed inside DN lock.
> Thoughts?



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)