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https://issues.apache.org/jira/browse/AVRO-792?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Thiruvalluvan M. G. updated AVRO-792:
-------------------------------------
Fix Version/s: 1.5.1
Assignee: Thiruvalluvan M. G.
Status: Patch Available (was: Open)
The problem is because we are reusing ResolvingDecoder objects.
ResolvingDecoder objects are stateful and hence cannot be used simultaneously
to decode more than one stream. But constructing ResolvingDecoder is expensive.
So we cannot construct ResolvingDecoder objects whenever we need.
The real expensive part of ResolvingDecoder construction is construction of the
symbol table (actually a symbol tree). The symbol tree is stateless (in fact it
is immutable). Once the symbol tree is ready, construction of ResolvingDecoder
is cheap. Before the DecoderFactory refacroring, GenericDatumReader used to
cache the symbol tree (which was exposed through ResolvingDecoder.resolve()
method.)
The forthcoming patch fixes the problem by caching the symbol tree within the
ResolvingDecoder.
> map reduce job for avro 1.5 generates ArrayIndexOutOfBoundsException
> --------------------------------------------------------------------
>
> Key: AVRO-792
> URL: https://issues.apache.org/jira/browse/AVRO-792
> Project: Avro
> Issue Type: Bug
> Components: java
> Affects Versions: 1.5.0
> Environment: Mac with VMWare running Linux training-vm-Ubuntu
> Reporter: ey-chih chow
> Assignee: Thiruvalluvan M. G.
> Priority: Blocker
> Fix For: 1.5.1
>
> Original Estimate: 504h
> Remaining Estimate: 504h
>
> We have an avro map/reduce job used to be working with avro 1.4, but broken
> with avro 1.5. The M/R job with avro 1.5 worked fine under our debugging
> environment, but broken when we moved to a real cluster. At one instance f
> testing, the job had 23 reducers. Four of them succeeded and the rest failed
> because of the ArrayIndexOutOfBoundsException generated. Here are two
> instances of the stack traces:
> =================================================================================
> java.lang.ArrayIndexOutOfBoundsException: -1576799025
> at
> org.apache.avro.io.parsing.Symbol$Alternative.getSymbol(Symbol.java:364)
> at
> org.apache.avro.io.ResolvingDecoder.doAction(ResolvingDecoder.java:229)
> at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
> at
> org.apache.avro.io.ResolvingDecoder.readIndex(ResolvingDecoder.java:206)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
> at
> org.apache.avro.generic.GenericDatumReader.readMap(GenericDatumReader.java:232)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:141)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
> at
> org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:166)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:138)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:129)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperDeserializer.deserialize(AvroSerialization.java:86)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperDeserializer.deserialize(AvroSerialization.java:68)
> at
> org.apache.hadoop.mapred.Task$ValuesIterator.readNextValue(Task.java:1136)
> at org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1076)
> at
> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.moveToNext(ReduceTask.java:246)
> at
> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.next(ReduceTask.java:242)
> at
> org.apache.avro.mapred.HadoopReducerBase$ReduceIterable.next(HadoopReducerBase.java:47)
> at
> com.ngmoco.ngpipes.etl.NgEventETLReducer.reduce(NgEventETLReducer.java:46)
> at
> com.ngmoco.ngpipes.etl.NgEventETLReducer.reduce(NgEventETLReducer.java:1)
> at
> org.apache.avro.mapred.HadoopReducerBase.reduce(HadoopReducerBase.java:60)
> at
> org.apache.avro.mapred.HadoopReducerBase.reduce(HadoopReducerBase.java:30)
> at
> org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:468)
> at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:416)
> at org.apache.hadoop.mapred.Child$4.run(Child.java:240)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:396)
> at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1115)
> at org.apache.hadoop.mapred.Child.main(Child.java:234)
> =====================================================================================================
> java.lang.ArrayIndexOutOfBoundsException: 40
> at
> org.apache.avro.io.parsing.Symbol$Alternative.getSymbol(Symbol.java:364)
> at
> org.apache.avro.io.ResolvingDecoder.doAction(ResolvingDecoder.java:229)
> at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
> at
> org.apache.avro.io.ResolvingDecoder.readIndex(ResolvingDecoder.java:206)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
> at
> org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:166)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:138)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:129)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperDeserializer.deserialize(AvroSerialization.java:86)
> at
> org.apache.avro.mapred.AvroSerialization$AvroWrapperDeserializer.deserialize(AvroSerialization.java:68)
> at
> org.apache.hadoop.mapred.Task$ValuesIterator.readNextValue(Task.java:1136)
> at org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1076)
> at
> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.moveToNext(ReduceTask.java:246)
> at
> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.next(ReduceTask.java:242)
> at
> org.apache.avro.mapred.HadoopReducerBase$ReduceIterable.next(HadoopReducerBase.java:47)
> at
> com.ngmoco.ngpipes.sourcing.sessions.NgSessionReducer.reduce(NgSessionReducer.java:74)
> at
> com.ngmoco.ngpipes.sourcing.sessions.NgSessionReducer.reduce(NgSessionReducer.java:1)
> at
> org.apache.avro.mapred.HadoopReducerBase.reduce(HadoopReducerBase.java:60)
> at
> org.apache.avro.mapred.HadoopReducerBase.reduce(HadoopReducerBase.java:30)
> at
> org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:468)
> at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:416)
> at org.apache.hadoop.mapred.Child$4.run(Child.java:240)
> at java.security.AccessController.doPrivileged(Native Method)
> at javax.security.auth.Subject.doAs(Subject.java:396)
> at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1115)
> at org.apache.hadoop.mapred.Child.main(Child.java:234)
> =====================================================================================================
> The signature of our map() is:
> public void map(Utf8 input, AvroCollector<Pair<Utf8, GenericRecord>>
> collector, Reporter reporter) throws IOException;
> and reduce() is:
> public void reduce(Utf8 key, Iterable<GenericRecord> values,
> AvroCollector<GenericRecord> collector, Reporter reporter) throws IOException;
> All the GenericRecords are of the same schema.
> There are many changes in the area of serialization/de-serailization between
> avro 1.4 and 1.5, but could not figure out why the exceptions were generated.
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