[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12996845#comment-12996845
]
Hadoop QA commented on HDFS-925:
-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12470272/HDFS-925.patch
against trunk revision 1072023.
+1 @author. The patch does not contain any @author tags.
+1 tests included. The patch appears to include 5 new or modified tests.
+1 javadoc. The javadoc tool did not generate any warning messages.
+1 javac. The applied patch does not increase the total number of javac
compiler warnings.
+1 findbugs. The patch does not introduce any new Findbugs (version 1.3.9)
warnings.
+1 release audit. The applied patch does not increase the total number of
release audit warnings.
-1 core tests. The patch failed these core unit tests:
org.apache.hadoop.hdfs.TestFileConcurrentReader
-1 contrib tests. The patch failed contrib unit tests.
+1 system test framework. The patch passed system test framework compile.
Test results:
https://hudson.apache.org/hudson/job/PreCommit-HDFS-Build/200//testReport/
Findbugs warnings:
https://hudson.apache.org/hudson/job/PreCommit-HDFS-Build/200//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output:
https://hudson.apache.org/hudson/job/PreCommit-HDFS-Build/200//console
This message is automatically generated.
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Assignee: Steve Loughran
Priority: Minor
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch,
HDFS-925.patch, HDFS-925.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
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For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12993859#comment-12993859
]
Steve Loughran commented on HDFS-925:
-
Reviewing the JT code, this is still a problem: the JobTracker does call
FileSystem.get(); MAPREDUCE-437 talks about this. This patch merely makes it
easier to diagnose who else closed the shared instance, not prevent it.
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Assignee: Steve Loughran
Priority: Minor
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch,
HDFS-925.patch, HDFS-925.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12990700#comment-12990700
]
Steve Loughran commented on HDFS-925:
-
The latest patch adds a test for expected behaviour.
1. If you call FileSystem.get(conf) you get a shared client, if you ask for a
new instance, you get a different instance.
2. If you close any of the shared instances, all other attempts to use that
shared instance will fail.
3. If you call FileSystem.getNewInstance(conf), that configuration is different.
4. If, after closing a shared client instance, if you call FileSystem.get(conf)
, you get a new instance.
This whole thing dates to an incompatible change made to cache shared clients.
It doesn't work across threads, not reliably. Either the clients are reference
counted, or you call getNewInstance() to get a thread safe instance. I think
I've moved my code to the new API call, its been out there for a while now, but
this helps track down problems for people who haven't moved.
Even if people don't want the extra diagnostics (pity), the test could be used
to verify the semantics of FileSystem.get() and FileSystem.getNewInstance().
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Assignee: Steve Loughran
Priority: Minor
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch,
HDFS-925.patch, HDFS-925.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12979557#action_12979557
]
Steve Loughran commented on HDFS-925:
-
I'm not seeing this as a problem so much as I'm doing less hadoop work
directly, and what I am doing is doing more in separate processes. I fear the
problem still exists though.
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Assignee: Steve Loughran
Priority: Minor
Fix For: 0.22.0
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12976156#action_12976156
]
Konstantin Shvachko commented on HDFS-925:
--
Is this still a problem?
Could you please provide a test case for the failure condition.
In the patch I didn't like that you effectively pass a message via the
Exception variable.
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Assignee: Steve Loughran
Priority: Minor
Fix For: 0.22.0
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Commented: (HDFS-925) Make it harder to accidentally close a shared DFSClient
[
https://issues.apache.org/jira/browse/HDFS-925?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12833775#action_12833775
]
Hadoop QA commented on HDFS-925:
-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12435708/HDFS-925.patch
against trunk revision 908628.
+1 @author. The patch does not contain any @author tags.
-1 tests included. 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.
+1 javadoc. The javadoc tool did not generate any warning messages.
+1 javac. The applied patch does not increase the total number of javac
compiler warnings.
+1 findbugs. The patch does not introduce any new Findbugs warnings.
+1 release audit. The applied patch does not increase the total number of
release audit warnings.
-1 core tests. The patch failed core unit tests.
-1 contrib tests. The patch failed contrib unit tests.
Test results:
http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h5.grid.sp2.yahoo.net/230/testReport/
Findbugs warnings:
http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h5.grid.sp2.yahoo.net/230/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results:
http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h5.grid.sp2.yahoo.net/230/artifact/trunk/build/test/checkstyle-errors.html
Console output:
http://hudson.zones.apache.org/hudson/job/Hdfs-Patch-h5.grid.sp2.yahoo.net/230/console
This message is automatically generated.
Make it harder to accidentally close a shared DFSClient
---
Key: HDFS-925
URL: https://issues.apache.org/jira/browse/HDFS-925
Project: Hadoop HDFS
Issue Type: Improvement
Components: hdfs client
Affects Versions: 0.21.0
Reporter: Steve Loughran
Priority: Minor
Fix For: 0.22.0
Attachments: HADOOP-5933.patch, HADOOP-5933.patch, HDFS-925.patch
Every so often I get stack traces telling me that DFSClient is closed,
usually in {{org.apache.hadoop.hdfs.DFSClient.checkOpen() }} . The root cause
of this is usually that one thread has closed a shared fsclient while another
thread still has a reference to it. If the other thread then asks for a new
client it will get one -and the cache repopulated- but if has one already,
then I get to see a stack trace.
It's effectively a race condition between clients in different threads.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
