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https://issues.apache.org/jira/browse/DRILL-4884?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15604196#comment-15604196
]
ASF GitHub Bot commented on DRILL-4884:
---------------------------------------
Github user jinfengni commented on a diff in the pull request:
https://github.com/apache/drill/pull/584#discussion_r84831079
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/validate/IteratorValidatorBatchIterator.java
---
@@ -301,7 +301,7 @@ public IterOutcome next() {
"Incoming batch [#%d, %s] has an empty schema. This is
not allowed.",
instNum, batchTypeName));
}
- if (incoming.getRecordCount() > MAX_BATCH_SIZE) {
+ if (incoming.getRecordCount() >= MAX_BATCH_SIZE) {
--- End diff --
Drill requires that batch with no selection vector(SV), and batch with SV2
is bounded by 65536. This requirement is valid across the entire Drill code
base. What this IteratorVAlidator tries to enforce is to make sure every
incoming batch meet this requirement, when assertion is enabled. However, it's
each operator's responsibility to enforce this. For instance, as you saw, each
reader in Drill should produce a batch no larger than 65536. If you develop a
new storage plugin with a new reader, then the new reader should enforce this
rule as well.
Therefore, in your situation where you develop a new reader, the right
approach is that you need make sure reader produces batch no larger than this
threshold.
The original code IteratorValidatorBatchIterator.java should be fine. For
the repo I tried, I feel the fix should be in LimitRecordBatch.java. As you
indicated earlier, the index "i" is defined as char, which is not right.
Would you like to modify your patch ?
> Drill produced IOB exception while querying data of 65536 limitation using
> non batched reader
> ---------------------------------------------------------------------------------------------
>
> Key: DRILL-4884
> URL: https://issues.apache.org/jira/browse/DRILL-4884
> Project: Apache Drill
> Issue Type: Bug
> Components: Query Planning & Optimization
> Affects Versions: 1.8.0
> Environment: CentOS 6.5 / JAVA 8
> Reporter: Hongze Zhang
> Assignee: Jinfeng Ni
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> Drill produces IOB while using a non batched scanner and limiting SQL by
> 65536.
> SQL:
> {noformat}
> select id from xx limit 1 offset 65535
> {noformat}
> Result:
> {noformat}
> at
> org.apache.drill.common.exceptions.UserException$Builder.build(UserException.java:534)
> ~[classes/:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor.sendFinalState(FragmentExecutor.java:324)
> [classes/:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor.cleanup(FragmentExecutor.java:184)
> [classes/:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor.run(FragmentExecutor.java:290)
> [classes/:na]
> at
> org.apache.drill.common.SelfCleaningRunnable.run(SelfCleaningRunnable.java:38)
> [classes/:na]
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> [na:1.8.0_101]
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> [na:1.8.0_101]
> at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101]
> Caused by: java.lang.IndexOutOfBoundsException: index: 131072, length: 2
> (expected: range(0, 131072))
> at io.netty.buffer.DrillBuf.checkIndexD(DrillBuf.java:175)
> ~[classes/:4.0.27.Final]
> at io.netty.buffer.DrillBuf.chk(DrillBuf.java:197)
> ~[classes/:4.0.27.Final]
> at io.netty.buffer.DrillBuf.setChar(DrillBuf.java:517)
> ~[classes/:4.0.27.Final]
> at
> org.apache.drill.exec.record.selection.SelectionVector2.setIndex(SelectionVector2.java:79)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.limit.LimitRecordBatch.limitWithNoSV(LimitRecordBatch.java:167)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.limit.LimitRecordBatch.doWork(LimitRecordBatch.java:145)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractSingleRecordBatch.innerNext(AbstractSingleRecordBatch.java:93)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.limit.LimitRecordBatch.innerNext(LimitRecordBatch.java:115)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:162)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.validate.IteratorValidatorBatchIterator.next(IteratorValidatorBatchIterator.java:215)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:119)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:109)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractSingleRecordBatch.innerNext(AbstractSingleRecordBatch.java:51)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.svremover.RemovingRecordBatch.innerNext(RemovingRecordBatch.java:94)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:162)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.validate.IteratorValidatorBatchIterator.next(IteratorValidatorBatchIterator.java:215)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:119)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:109)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractSingleRecordBatch.innerNext(AbstractSingleRecordBatch.java:51)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.project.ProjectRecordBatch.innerNext(ProjectRecordBatch.java:132)
> ~[classes/:na]
> at
> org.apache.drill.exec.record.AbstractRecordBatch.next(AbstractRecordBatch.java:162)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.validate.IteratorValidatorBatchIterator.next(IteratorValidatorBatchIterator.java:215)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.BaseRootExec.next(BaseRootExec.java:104)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.ScreenCreator$ScreenRoot.innerNext(ScreenCreator.java:81)
> ~[classes/:na]
> at
> org.apache.drill.exec.physical.impl.BaseRootExec.next(BaseRootExec.java:94)
> ~[classes/:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor$1.run(FragmentExecutor.java:256)
> ~[classes/:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor$1.run(FragmentExecutor.java:250)
> ~[classes/:na]
> at java.security.AccessController.doPrivileged(Native Method)
> ~[na:1.8.0_101]
> at javax.security.auth.Subject.doAs(Subject.java:422) ~[na:1.8.0_101]
> at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
> ~[hadoop-common-2.7.1.jar:na]
> at
> org.apache.drill.exec.work.fragment.FragmentExecutor.run(FragmentExecutor.java:250)
> [classes/:na]
> ... 4 common frames omitted
> {noformat}
> Code from IteratorValidatorBatchIterator.java said that it is OK incoming
> returning 65536 records:
> {noformat}
> if (incoming.getRecordCount() > MAX_BATCH_SIZE) { // MAX_BATCH_SIZE == 65536
> throw new IllegalStateException(
> String.format(
> "Incoming batch [#%d, %s] has size %d, which is beyond the"
> + " limit of %d",
> instNum, batchTypeName, incoming.getRecordCount(),
> MAX_BATCH_SIZE
> ));
> }
> {noformat}
> Code from LimitRecordBatch.java shows that a loop will not break as expected
> when the incoming returns 65536 records:
> {noformat}
> private void limitWithNoSV(int recordCount) {
> final int offset = Math.max(0, Math.min(recordCount - 1, recordsToSkip));
> recordsToSkip -= offset;
> int fetch;
> if(noEndLimit) {
> fetch = recordCount;
> } else {
> fetch = Math.min(recordCount, offset + recordsLeft);
> recordsLeft -= Math.max(0, fetch - offset);
> }
> int svIndex = 0;
> for(char i = (char) offset; i < fetch; svIndex++, i++) { // since
> fetch==recordCount==65536, param i can be increased from 65535 to 65536, then
> be limited to 0 by the char type limitation, the loop abnormally continues.
> outgoingSv.setIndex(svIndex, i);
> }
> outgoingSv.setRecordCount(svIndex);
> }
> {noformat}
> The IllegalStateException should be thrown when incoming returns 65535
> records rather than 65536.
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