java.lang.OutOfMemoryError: Java heap space (Reopen of PIG-766)
---------------------------------------------------------------
Key: PIG-1442
URL: https://issues.apache.org/jira/browse/PIG-1442
Project: Pig
Issue Type: Bug
Components: impl
Affects Versions: 0.7.0, 0.2.0
Environment: Apache-Hadoop 0.20.2 + Pig 0.7.0 and also for 0.8.0-dev
(18/may)
Hadoop-0.18.3 (cloudera RPMs) + PIG 0.2.0
Reporter: Dirk Schmid
As mentioned by Ashutosh this is a reopen of
https://issues.apache.org/jira/browse/PIG-766 because there is still a problem
which causes that PIG scales only by memory.
For convenience here comes the last entry of the PIG-766-Jira-Ticket:
{quote}1. Are you getting the exact same stack trace as mentioned in the
jira?{quote} Yes the same and some similar traces:
{noformat}
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2786)
at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:94)
at java.io.DataOutputStream.write(DataOutputStream.java:90)
at java.io.FilterOutputStream.write(FilterOutputStream.java:80)
at
org.apache.pig.data.DataReaderWriter.writeDatum(DataReaderWriter.java:279)
at org.apache.pig.data.DefaultTuple.write(DefaultTuple.java:264)
at
org.apache.pig.data.DefaultAbstractBag.write(DefaultAbstractBag.java:249)
at
org.apache.pig.data.DataReaderWriter.writeDatum(DataReaderWriter.java:214)
at org.apache.pig.data.DefaultTuple.write(DefaultTuple.java:264)
at
org.apache.pig.data.DataReaderWriter.writeDatum(DataReaderWriter.java:209)
at org.apache.pig.data.DefaultTuple.write(DefaultTuple.java:264)
at
org.apache.pig.impl.io.PigNullableWritable.write(PigNullableWritable.java:123)
at
org.apache.hadoop.io.serializer.WritableSerialization$WritableSerializer.serialize(WritableSerialization.java:90)
at
org.apache.hadoop.io.serializer.WritableSerialization$WritableSerializer.serialize(WritableSerialization.java:77)
at org.apache.hadoop.mapred.IFile$Writer.append(IFile.java:179)
at
org.apache.hadoop.mapred.Task$CombineOutputCollector.collect(Task.java:880)
at
org.apache.hadoop.mapred.Task$NewCombinerRunner$OutputConverter.write(Task.java:1201)
at
org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.processOnePackageOutput(PigCombiner.java:199)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:161)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:51)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176)
at
org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1222)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.doInMemMerge(ReduceTask.java:2563)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.run(ReduceTask.java:2501)
java.lang.OutOfMemoryError: Java heap space
at org.apache.pig.data.DefaultTuple.(DefaultTuple.java:58)
at
org.apache.pig.data.DefaultTupleFactory.newTuple(DefaultTupleFactory.java:35)
at
org.apache.pig.data.DataReaderWriter.bytesToTuple(DataReaderWriter.java:61)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:142)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:136)
at
org.apache.pig.data.DefaultAbstractBag.readFields(DefaultAbstractBag.java:263)
at
org.apache.pig.data.DataReaderWriter.bytesToBag(DataReaderWriter.java:71)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:145)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:136)
at
org.apache.pig.data.DataReaderWriter.bytesToTuple(DataReaderWriter.java:63)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:142)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:136)
at org.apache.pig.data.DefaultTuple.readFields(DefaultTuple.java:284)
at
org.apache.pig.impl.io.PigNullableWritable.readFields(PigNullableWritable.java:114)
at
org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:67)
at
org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:40)
at
org.apache.hadoop.mapreduce.ReduceContext.nextKeyValue(ReduceContext.java:116)
at
org.apache.hadoop.mapreduce.ReduceContext$ValueIterator.next(ReduceContext.java:163)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POCombinerPackage.getNext(POCombinerPackage.java:155)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POMultiQueryPackage.getNext(POMultiQueryPackage.java:242)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.processOnePackageOutput(PigCombiner.java:170)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:161)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:51)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176)
at
org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1222)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.doInMemMerge(ReduceTask.java:2563)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.run(ReduceTask.java:2501)
java.lang.OutOfMemoryError: Java heap space
at java.util.ArrayList.(ArrayList.java:112)
at org.apache.pig.data.DefaultTuple.(DefaultTuple.java:58)
at
org.apache.pig.data.DefaultTupleFactory.newTuple(DefaultTupleFactory.java:35)
at
org.apache.pig.data.DataReaderWriter.bytesToTuple(DataReaderWriter.java:61)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:142)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:136)
at
org.apache.pig.data.DefaultAbstractBag.readFields(DefaultAbstractBag.java:263)
at
org.apache.pig.data.DataReaderWriter.bytesToBag(DataReaderWriter.java:71)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:145)
at
org.apache.pig.data.DataReaderWriter.readDatum(DataReaderWriter.java:136)
at org.apache.pig.data.DefaultTuple.readFields(DefaultTuple.java:284)
at
org.apache.pig.data.InternalCachedBag$CachedBagIterator.hasNext(InternalCachedBag.java:221)
at
org.apache.pig.builtin.Distinct.getDistinctFromNestedBags(Distinct.java:138)
at org.apache.pig.builtin.Distinct.access$200(Distinct.java:40)
at org.apache.pig.builtin.Distinct$Intermediate.exec(Distinct.java:103)
at org.apache.pig.builtin.Distinct$Intermediate.exec(Distinct.java:96)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:209)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:250)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:341)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:289)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:276)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLocalRearrange.getNext(POLocalRearrange.java:259)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.PODemux.runPipeline(PODemux.java:217)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.PODemux.getNext(PODemux.java:207)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.processOnePackageOutput(PigCombiner.java:183)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:161)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:51)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176)
at
org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1222)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.doInMemMerge(ReduceTask.java:2563)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$InMemFSMergeThread.run(ReduceTask.java:2501)
{noformat}
{quote}
2. Which operations are you doing in your query - join, group-by, any other ?
3. What load/store func are you using to read and write data? PigStorage or
your own ?
4. What is your data size and memory available to your tasks?
5. Do you have very large records in your dataset, like hundreds of MB for one
record ?
It would be great if you can paste here the script from which you get this
exception.
{quote}
As we started to test the transformation (see below) the OutOfMemory-Error
first occured at input-datasets of about 150MB.
Increasing the Memory for the child-vms by setting {{mapred.child.java.opts}}
to {{600m}} fixed it for a while.
When using larger input-dataset the problem reappears.
*Input-Data:*
A CSV-File, ~14GB Dataset, ~100,000,000 Records per Dataset, ~145 Byte per
Record
*Example:*
{noformat}
USER_ID REQUEST_DATE SESSION
COMPANY SERVICENAME SECTION_1 SECTION_2 SECTION_3 SECTION_4
SECTION_5 SECTION_6 SECTION SECTION_NEW
ac14263e-22082-2263455080-9 2010-03-02
ac14263e-22082-2263455080-9-1273015305 ABC (NULL) main (NULL)
(NULL) (NULL) (NULL) abc/main/mail /main/mail
...
...
{noformat}
*The Pig-Script*
{code}
A = LOAD 'full_load' USING PigStorage('\t');
B = FOREACH A GENERATE $4 AS servicename, $3 AS company, $2 AS session, $0 as
user_id
, $5 AS section_1, $6 AS section_2, $7 AS section_3, $8
as section_4
, $9 as section_5, $10 as section_6, $11 AS section;
/* 1st aggregation */
S0 = GROUP B BY (servicename, company);
S0_A = FOREACH S0 {
unique_clients = DISTINCT B.user_id;
visits = DISTINCT B.session;
GENERATE FLATTEN(group), COUNT(B) AS pi_count,
COUNT(unique_clients) AS unique_clients_count, COUNT(visits) AS visit_count;
}
S0_B = FOREACH S0_A GENERATE servicename, company, '' as section_1, '' as
section_2, '' as section_3, '' as section_4
, '' as section_5, '' as section_6, '' as section,
pi_count, unique_clients_count
, visit_count, 0 as level;
/* 2nd aggregation */
S1 = GROUP B BY (servicename, company, section_1); S1_A = FOREACH S1 {
unique_clients = DISTINCT B.user_id;
visits = DISTINCT B.session;
GENERATE FLATTEN(group), COUNT(B) AS pi_count,
COUNT(unique_clients) AS unique_clients_count, COUNT(visits) AS visit_count;
}
S1_B = FOREACH S1_A GENERATE servicename, company, section_1, '' as section_2,
'' as section_3, '' as section_4
, '' as section_5, '' as section_6, '' as section,
pi_count, unique_clients_count
, visit_count, 1 as level;
/* 3rd - 7th aggregation may follow here */
/* build result*/
X = UNION S0_B, S1_B;
STORE X INTO 'result' USING PigStorage ('\t'); {code}
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