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Posted to issues@hive.apache.org by "tartarus (JIRA)" <ji...@apache.org> on 2018/03/22 12:39:00 UTC
[jira] [Commented] (HIVE-14303)
CommonJoinOperator.checkAndGenObject should return directly to avoid NPE if
ExecReducer.close is called twice.
[ https://issues.apache.org/jira/browse/HIVE-14303?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16409454#comment-16409454 ]
tartarus commented on HIVE-14303:
---------------------------------
[~csun] [~zxu] I suggest adding some exception information in the
{code:java}
ExecReducer.close(){code}
. We should find the reason for the first close failure. It is exactly what I have done.
> CommonJoinOperator.checkAndGenObject should return directly to avoid NPE if ExecReducer.close is called twice.
> --------------------------------------------------------------------------------------------------------------
>
> Key: HIVE-14303
> URL: https://issues.apache.org/jira/browse/HIVE-14303
> Project: Hive
> Issue Type: Bug
> Reporter: zhihai xu
> Assignee: zhihai xu
> Priority: Major
> Fix For: 2.3.0
>
> Attachments: HIVE-14303.0.patch, HIVE-14303.1.patch, HIVE-14303.2.patch
>
>
> CommonJoinOperator.checkAndGenObject should return directly (after {{CommonJoinOperator.closeOp}} was called ) to avoid NPE if ExecReducer.close is called twice. ExecReducer.close implements Closeable interface and ExecReducer.close can be called multiple time. We saw the following NPE which hide the real exception due to this bug.
> {code:java}
> Error: java.lang.RuntimeException: Hive Runtime Error while closing operators: null
> at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.close(ExecReducer.java:296)
> at org.apache.hadoop.io.IOUtils.cleanup(IOUtils.java:244)
> at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:459)
> at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:392)
> at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:163)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:415)
> at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1671)
> at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
> Caused by: java.lang.NullPointerException
> at org.apache.hadoop.hive.ql.exec.CommonJoinOperator.checkAndGenObject(CommonJoinOperator.java:718)
> at org.apache.hadoop.hive.ql.exec.JoinOperator.endGroup(JoinOperator.java:256)
> at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.close(ExecReducer.java:284)
> ... 8 more
> {code}
> The code from ReduceTask.runOldReducer:
> {code:java}
> reducer.close(); //line 453
> reducer = null;
>
> out.close(reporter);
> out = null;
> } finally {
> IOUtils.cleanup(LOG, reducer);// line 459
> closeQuietly(out, reporter);
> }
> {code}
> Based on the above stack trace and code, reducer.close() is called twice because the exception happened when reducer.close() is called for the first time at line 453, the code exit before reducer was set to null. NullPointerException is triggered when reducer.close() is called for the second time in IOUtils.cleanup at line 459. NullPointerException hide the real exception which happened when reducer.close() is called for the first time at line 453.
> The reason for NPE is:
> The first reducer.close called CommonJoinOperator.closeOp which clear {{storage}}
> {code:java}
> Arrays.fill(storage, null);
> {code}
> the second reduce.close generated NPE due to null {{storage[alias]}} which is set to null by first reducer.close.
> The following reducer log can give more proof:
> {code:java}
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.JoinOperator: 0 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.JoinOperator: 0 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.JoinOperator: SKEWJOINFOLLOWUPJOBS:0
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.SelectOperator: 1 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.SelectOperator: 2 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.SelectOperator: 3 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.FileSinkOperator: 4 finished. closing...
> 2016-07-14 22:24:51,016 INFO [main] org.apache.hadoop.hive.ql.exec.FileSinkOperator: FS[4]: records written - 53466
> 2016-07-14 22:25:11,555 ERROR [main] ExecReducer: Hit error while closing operators - failing tree
> 2016-07-14 22:25:11,649 WARN [main] org.apache.hadoop.mapred.YarnChild: Exception running child : java.lang.RuntimeException: Hive Runtime Error while closing operators: null
> at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.close(ExecReducer.java:296)
> at org.apache.hadoop.io.IOUtils.cleanup(IOUtils.java:244)
> at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:459)
> at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:392)
> at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:163)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:415)
> at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1671)
> at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
> Caused by: java.lang.NullPointerException
> at org.apache.hadoop.hive.ql.exec.CommonJoinOperator.checkAndGenObject(CommonJoinOperator.java:718)
> at org.apache.hadoop.hive.ql.exec.JoinOperator.endGroup(JoinOperator.java:256)
> at org.apache.hadoop.hive.ql.exec.mr.ExecReducer.close(ExecReducer.java:284)
> ... 8 more
> {code}
>
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