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https://issues.apache.org/jira/browse/KYLIN-1834?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15464661#comment-15464661
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liyang commented on KYLIN-1834:
-------------------------------
Before the fix, dictionary broke down around 1GB I guess.
After the fix, 2GB is the upper limit of dictionary size. And a clear error
will be thrown the size goes beyond.
> java.lang.IllegalArgumentException: Value not exists! - in Step 4 - Build
> Dimension Dictionary
> ----------------------------------------------------------------------------------------------
>
> Key: KYLIN-1834
> URL: https://issues.apache.org/jira/browse/KYLIN-1834
> Project: Kylin
> Issue Type: Bug
> Affects Versions: v1.5.2, v1.5.2.1
> Reporter: Richard Calaba
> Assignee: liyang
> Priority: Blocker
> Fix For: v1.5.4
>
> Attachments: job_2016_06_28_09_59_12-value-not-found.zip
>
>
> Getting exception in Step 4 - Build Dimension Dictionary:
> java.lang.IllegalArgumentException: Value not exists!
> at
> org.apache.kylin.dimension.Dictionary.getIdFromValueBytes(Dictionary.java:160)
> at
> org.apache.kylin.dict.TrieDictionary.getIdFromValueImpl(TrieDictionary.java:158)
> at
> org.apache.kylin.dimension.Dictionary.getIdFromValue(Dictionary.java:96)
> at
> org.apache.kylin.dimension.Dictionary.getIdFromValue(Dictionary.java:76)
> at
> org.apache.kylin.dict.lookup.SnapshotTable.takeSnapshot(SnapshotTable.java:96)
> at
> org.apache.kylin.dict.lookup.SnapshotManager.buildSnapshot(SnapshotManager.java:106)
> at
> org.apache.kylin.cube.CubeManager.buildSnapshotTable(CubeManager.java:215)
> at
> org.apache.kylin.cube.cli.DictionaryGeneratorCLI.processSegment(DictionaryGeneratorCLI.java:59)
> at
> org.apache.kylin.cube.cli.DictionaryGeneratorCLI.processSegment(DictionaryGeneratorCLI.java:42)
> at
> org.apache.kylin.engine.mr.steps.CreateDictionaryJob.run(CreateDictionaryJob.java:56)
> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
> at
> org.apache.kylin.engine.mr.common.HadoopShellExecutable.doWork(HadoopShellExecutable.java:60)
> at
> org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:114)
> at
> org.apache.kylin.job.execution.DefaultChainedExecutable.doWork(DefaultChainedExecutable.java:50)
> at
> org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:114)
> at
> org.apache.kylin.job.impl.threadpool.DefaultScheduler$JobRunner.run(DefaultScheduler.java:124)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:745)
> result code:2
> The code which generates the exception is:
> org.apache.kylin.dimension.Dictionary.java:
> /**
> * A lower level API, return ID integer from raw value bytes. In case of
> not found
> * <p>
> * - if roundingFlag=0, throw IllegalArgumentException; <br>
> * - if roundingFlag<0, the closest smaller ID integer if exist; <br>
> * - if roundingFlag>0, the closest bigger ID integer if exist. <br>
> * <p>
> * Bypassing the cache layer, this could be significantly slower than
> getIdFromValue(T value).
> *
> * @throws IllegalArgumentException
> * if value is not found in dictionary and rounding is off;
> * or if rounding cannot find a smaller or bigger ID
> */
> final public int getIdFromValueBytes(byte[] value, int offset, int len,
> int roundingFlag) throws IllegalArgumentException {
> if (isNullByteForm(value, offset, len))
> return nullId();
> else {
> int id = getIdFromValueBytesImpl(value, offset, len,
> roundingFlag);
> if (id < 0)
> throw new IllegalArgumentException("Value not exists!");
> return id;
> }
> }
> ==========================================================
> The Cube is big - fact 110 mio rows, the largest dimension (customer) has 10
> mio rows. I have increased the JVM -Xmx to 16gb and set the
> kylin.table.snapshot.max_mb=2048 in kylin.properties to make sure the Cube
> build doesn't fail (previously we were getting exception complaining about
> the 300MB limit for Dimension dictionary size (req. approx 700MB)).
> ==========================================================
> Before that we were getting exception complaining about the Dictionary
> encoding problem - "Too high cardinality is not suitable for dictionary --
> cardinality: 10873977" - this we resolved by changing the affected
> dimension/row key Encoding from "dict" to "int; length=8" on the Advanced
> Settings of the Cube.
> ==========================================================
> We have 2 high-cardinality fields (one from fact table and one from the big
> dimension (customer - see above). We need to use in distinc_count measure for
> our calculations. I wonder if this exception Value not found! is somewhat
> related ??? Those count_distinct measures are defined one with return type
> "bitmap" (exact precission - only for Int columns) and 2nd with return type
> "hllc16" (error rate <= 1.22 %)
> ==========================================================
> I am looking for any clues to debug the cause of this error and way how to
> circumwent this ...
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