[jira] Commented: (PIG-1828) HBaseStorage has problems with processing multiregion tables

["Dmitriy V. Ryaboy (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-1828?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12987979#action_12987979 ] 

Dmitriy V. Ryaboy commented on PIG-1828:
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Found the issue!

Turns out HBaseStorage is doing the right thing and returning the correct set of splits; but PIG-1518 is merging the splits back into a single split! No wonder I wasn't seeing it, i was running with combinations turned off.

Short term fix: set pig.splitCombination to false.

Long term fix: I added OrderedLoadFunc implementation to the loader, so that PIG-1518 doesn't apply. I think this is correct, since TableSplits are in fact comparable, but I am not sure what exact consequences implementing this interface will have with regards to merge joins and such.  Ashutosh, can you comment?

For the folks using the EB version -- you are not affected, since this is only a 0.8 problem.

> HBaseStorage has problems with processing multiregion tables
> ------------------------------------------------------------
>
>                 Key: PIG-1828
>                 URL: https://issues.apache.org/jira/browse/PIG-1828
>             Project: Pig
>          Issue Type: Bug
>    Affects Versions: 0.8.0
>         Environment: Hadoop 0.20.2, Hbase 0.20.6, Distributed mode
>            Reporter: Lukas
>
> As brought up in the pig user mailing list (http://www.mail-archive.com/user%40pig.apache.org/msg00606.html) Pig does sometime not scan the full HBase table.
> It seems that HBaseStorage has problems scanning large tables. It issues just one mapper job instead of one mapper job per table region.
> Ian Stevens, who brought this issue up in the mailing list, attached a script to reproduce the problem (https://gist.github.com/766929).
> However, in my case, the problem only occurred, after the table was split into more than one regions.

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