Hi Serega,
Default task attempts = 4
--> Yes, 4 task attempts
Do you use any "balancing" properties, for eaxmple
pig.exec.reducers.bytes.per.reducer
--> No
I suppose you have unbalanced data
--> I guess so
It's better to provide logs
--> Unfortunately not possible any more "May be cleaned up by Task Tracker, if
older logs"
Regards,
Nebo
________________________________________
From: Serega Sheypak [serega.shey...@gmail.com]
Sent: Friday, January 10, 2014 2:32 PM
To: user@pig.apache.org
Subject: Re: Spilling issue - Optimize "GROUP BY"
"and after trying it on several datanodes in the end it failes"
Default task attempts = 4?
1. It's better to provde logs
2. Do you use any "balancing" properties, for eaxmple
pig.exec.reducers.bytes.per.reducer ?
I suppose you have unbalanced data
2014/1/10 Zebeljan, Nebojsa <nebojsa.zebel...@adtech.com>
> Hi,
> I'm encountering for a "simple" pig script, spilling issues. All map
tasks
> and reducers succeed pretty fast except the last reducer!
> The last reducer always starts spilling after ~10mins and after trying it
> on several datanodes in the end it failes.
>
> Do you have any idea, how I could optimize the GROUP BY, so I don't run
> into spilling issues.
>
> Thanks in advance!
>
> Below the pig script:
> ###
> dataImport = LOAD <some data>;
> generatedData = FOREACH dataImport GENERATE Field_A, Field_B, Field_C;
> groupedData = GROUP generatedData BY (Field_B, Field_C);
>
> result = FOREACH groupedData {
> counter_1 = FILTER generatedData BY <some fields>;
> counter_2 = FILTER generatedData BY <some fields>;
> GENERATE
> group.Field_B,
> group.Field_C,
> COUNT(counter_1),
> COUNT(counter_2);
> }
>
> STORE result INTO <some path> USING PigStorage();
> ###
>
> Regards,
> Nebo
>
