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https://issues.apache.org/jira/browse/AVRO-813?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14747050#comment-14747050
 ] 

Lewis John McGibbney commented on AVRO-813:
-------------------------------------------

Can anyone confirm if the EOFException looks like the following?
{code}
Caused by: java.io.EOFException
        at org.apache.avro.io.BinaryDecoder.ensureBounds(BinaryDecoder.java:473)
        at org.apache.avro.io.BinaryDecoder.readInt(BinaryDecoder.java:128)
        at org.apache.avro.io.BinaryDecoder.readIndex(BinaryDecoder.java:423)
        at 
org.apache.avro.io.ResolvingDecoder.doAction(ResolvingDecoder.java:290)
        at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
        at 
org.apache.avro.io.ResolvingDecoder.readIndex(ResolvingDecoder.java:267)
        at 
org.apache.avro.generic.GenericDatumReader.readWithoutConversion(GenericDatumReader.java:178)
        at 
org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:152)
        at 
org.apache.avro.generic.GenericDatumReader.readField(GenericDatumReader.java:240)
        at 
org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:230)
        at 
org.apache.avro.generic.GenericDatumReader.readWithoutConversion(GenericDatumReader.java:174)
        at 
org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:152)
        at 
org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:144)
        at 
org.apache.hadoop.io.serializer.avro.AvroSerialization$AvroDeserializer.deserialize(AvroSerialization.java:127)
        at 
org.apache.hadoop.mapreduce.task.ReduceContextImpl.nextKeyValue(ReduceContextImpl.java:146)
        at 
org.apache.hadoop.mapreduce.task.ReduceContextImpl.nextKey(ReduceContextImpl.java:121)
        at 
org.apache.hadoop.mapreduce.lib.reduce.WrappedReducer$Context.nextKey(WrappedReducer.java:302)
        at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:170)
        at 
org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:627)
        at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:389)
        at 
org.apache.hadoop.mapred.LocalJobRunner$Job$ReduceTaskRunnable.run(LocalJobRunner.java:319)
        at 
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
{code}

> EOFException is thrown during normal operation
> ----------------------------------------------
>
>                 Key: AVRO-813
>                 URL: https://issues.apache.org/jira/browse/AVRO-813
>             Project: Avro
>          Issue Type: Bug
>          Components: java
>    Affects Versions: 1.5.0
>            Reporter: Bruno Dumon
>            Assignee: Bruno Dumon
>              Labels: memex
>             Fix For: 1.8.0
>
>         Attachments: avro-813-patch.txt
>
>
> In an application that uses Avro as RPC mechanism (with the NettyTransceiver, 
> but that's irrelevant), I've noticed in jprofiler that during normal 
> operation quite some time was spent creating EOFExceptions:
> {noformat}
>   5.4% - 2,004 ms org.apache.avro.ipc.generic.GenericResponder.readRequest
>   5.0% - 1,871 ms org.apache.avro.generic.GenericDatumReader.read
>   4.9% - 1,832 ms org.apache.avro.generic.GenericDatumReader.read
>   4.9% - 1,832 ms org.apache.avro.generic.GenericDatumReader.readRecord
>   4.5% - 1,670 ms org.apache.avro.generic.GenericDatumReader.read
>   4.5% - 1,670 ms org.apache.avro.generic.GenericDatumReader.readRecord
>   4.3% - 1,596 ms org.apache.avro.generic.GenericDatumReader.read
>   2.8% - 1,048 ms org.apache.avro.generic.GenericDatumReader.readArray
>   1.3% - 477 ms org.apache.avro.io.ValidatingDecoder.arrayNext
>   1.3% - 471 ms org.apache.avro.io.BinaryDecoder.arrayNext
>   1.3% - 466 ms org.apache.avro.io.BinaryDecoder.doReadItemCount
>   1.3% - 466 ms org.apache.avro.io.BinaryDecoder.readLong
>   1.3% - 466 ms org.apache.avro.io.BinaryDecoder.ensureBounds
>   1.3% - 466 ms org.apache.avro.io.BinaryDecoder$ByteSource.compactAndFill
>   1.3% - 466 ms 
> org.apache.avro.io.BinaryDecoder$InputStreamByteSource.tryReadRaw
>   1.3% - 466 ms org.apache.avro.util.ByteBufferInputStream.read
>   1.3% - 466 ms org.apache.avro.util.ByteBufferInputStream.getBuffer
>   1.3% - 466 ms java.io.EOFException.<init>
>   1.3% - 466 ms java.io.IOException.<init>
>   1.2% - 460 ms java.lang.Exception.<init>
>   1.2% - 460 ms java.lang.Throwable.<init>
>   1.2% - 460 ms java.lang.Throwable.fillInStackTrace
> {noformat}
> These exceptions are produced by the ByteBufferInputStream (which modifies 
> InputStream's contract: return -1 at eof), but are catched higher up by the 
> tryReadRaw method.
> What happens is this:
> The message in question has an (empty) array at the end of its message, thus 
> the reader tries to read the size of this array in BinaryDecoder.readLong. 
> This calls ensureBounds(10), whose contract is that it should read 10 bytes 
> if they are available, and otherwise be quiet. ensureBounds calls via 
> compactAndFill the tryReadRaw method. It is this method which catches the 
> EOFException, because it only 'tries' to read so many bytes.
> Note that InputStreamByteSource.readRaw (without the 'try' part) does itself 
> check if read < 0 in order to throw EOFException, making the throwing of 
> EOFException in ByteBufferInputStream unnecessary (for this particular usage).
> There was some talk about EOFException in AVRO-392 too, though it seems this 
> particular common case was not mentioned there. When using Avro RPC, or more 
> in general, when using Avro to read small messages rather than large files, 
> it seems like one can very easily run into this EOFException situation, which 
> hurts performance.
> I'll attach a patch which simply removes the throwing of EOFException in 
> ByteBufferInputStream, but this will likely break other cases which rely on 
> the EOFException being thrown (haven't researched this to the bottom).



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