Too many spills to files causes ArrayIndexOutOfBoundsException if new temp file
cant be created
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Key: PIG-89
URL: https://issues.apache.org/jira/browse/PIG-89
Project: Pig
Issue Type: Bug
Components: data
Environment: Linux, Local execution Mode, JDK 1.6
Reporter: Craig Macdonald
Hello,
I am experimenting, trying to perform a DISTINCT on a medium sized set of URLs
- about 3million (same set as I discussed previously - Utkarsh has a copy),
this time in local execution mode.
Pig script:
{{{
A = LOAD 'all_13122007.txt';
B = DISTINCT A;
store B into 'bla;
}}}
Bring these errors (two lines swapped in DefaultDatabag) to find real error.
{{{
2008-02-04 18:09:44,756 [Low Memory Detector] INFO org.apache.pig - low memory
handler called init = 29491200(28800K) used = 269834064(263509K) committed =
307036160(299840K) max = 471662592(460608K)
2008-02-04 18:09:45,355 [Low Memory Detector] ERROR org.apache.pig - Unable to
spill contents to disk
java.io.IOException: Too many open files
at java.io.UnixFileSystem.createFileExclusively(Native Method)
at java.io.File.checkAndCreate(File.java:1704)
at java.io.File.createTempFile(File.java:1793)
at java.io.File.createTempFile(File.java:1830)
at org.apache.pig.data.DataBag.getSpillFile(DataBag.java:367)
at org.apache.pig.data.DefaultDataBag.spill(DefaultDataBag.java:69)
at
org.apache.pig.impl.util.SpillableMemoryManager.handleNotification(SpillableMemoryManager.java:123)
at
sun.management.NotificationEmitterSupport.sendNotification(NotificationEmitterSupport.java:138)
at sun.management.MemoryImpl.createNotification(MemoryImpl.java:171)
at
sun.management.MemoryPoolImpl$CollectionSensor.triggerAction(MemoryPoolImpl.java:300)
at sun.management.Sensor.trigger(Sensor.java:120)
java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.ArrayList.remove(ArrayList.java:390)
at org.apache.pig.data.DefaultDataBag.spill(DefaultDataBag.java:84)
at
org.apache.pig.impl.util.SpillableMemoryManager.handleNotification(SpillableMemoryManager.java:123)
at
sun.management.NotificationEmitterSupport.sendNotification(NotificationEmitterSupport.java:138)
at sun.management.MemoryImpl.createNotification(MemoryImpl.java:171)
at
sun.management.MemoryPoolImpl$CollectionSensor.triggerAction(MemoryPoolImpl.java:300)
at sun.management.Sensor.trigger(Sensor.java:120)
Exception in thread "Low Memory Detector" java.lang.InternalError: Error in
invoking listener
at
sun.management.NotificationEmitterSupport.sendNotification(NotificationEmitterSupport.java:141)
at sun.management.MemoryImpl.createNotification(MemoryImpl.java:171)
at
sun.management.MemoryPoolImpl$CollectionSensor.triggerAction(MemoryPoolImpl.java:300)
at sun.management.Sensor.trigger(Sensor.java:120)
}}}
There are a two sub-issues here:
1. Pig spills too much using a default JVM (64MB) size - expected?
Perhaps pig.pl should set a default JVM size of more than 64MB?
2. the line DefaultDataBag.java:84
{{{
mSpillFiles.remove(mSpillFiles.size() - 1);
}}}
line should check that mSpillFiles.size() > 0, because if File.createTempFile(
) in Databag.getSpillFile() fails, the mSpillFiles will not yet have been
updated. My preference would be to split try{ } catch (IOException ioe) { }
within DefaultDatabag.spill() into two exception handlers - one for
getSpillFile() errors, and one for actual writing errors (when we know
mSpillFiles has been added to).
If this latter point isnt coherent, I can create patch.
Ta muchly.
C
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