Hi Adam,

You're probably running into HBASE-2378. Give a single reducer a try, or
apply that patch (or move to 0.20.4)

Thanks
-Todd

On Mon, May 24, 2010 at 11:17 PM, Adam Silberstein
<[email protected]>wrote:

> Hi Todd,
> It's 0.20.3, and yes on multiple reducers.  We can try moving up to 0.20.4
> (and also a quick test with a single reducer).
>
> Thanks,
> Adam
>
>
> On 5/24/10 11:04 PM, "Todd Lipcon" <[email protected]> wrote:
>
> > Hi Adam,
> >
> > What version are you running, and are you using multiple reducers in your
> > HFileOutputFormat job? There was a bug in 0.20.3 which caused this case
> to
> > produce somewhat broken tables.
> >
> > -Todd
> >
> > On Mon, May 24, 2010 at 10:55 PM, Adam Silberstein
> > <[email protected]>wrote:
> >
> >> Hi,
> >> A colleague and I are working on testing a few HBase features, notably
> bulk
> >> import (mentioned in
> >>
> >>
> http://hadoop.apache.org/hbase/docs/current/api/org/apache/hadoop/hbase/mapr
> >> educe/package-summary.html) and running M/R jobs using HBase as input.
> >>
> >> We¹re taking the following steps:
> >> 1a. Load HBase with a M/R job using the normal API.
> >> OR
> >> 1b. Load HBase with bulk import.
> >>
> >> THEN
> >>
> >> 2a. Using the shell, do a ³count² over the table.
> >> OR
> >> 2b. Run a M/R job that scans the whole HBase table (and nothing else).
> >>
> >> Of the 4 combos, 3 are fine: 1a+2a, 1a+2b, 1b+2a.  We¹re having trouble
> >> with
> >> 1b+2b.  When we run the M/R job, it doesn¹t seem to read in any records,
> >> but
> >> there are no explicit errors in either the Hadoop or HBase logs.
> >>
> >> This seems odd.  It shouldn¹t matter how we load the table, and the
> shell¹s
> >> count operator seems to work correctly either way, counting all the
> >> records.
> >> The M/R job in 2b is the same no matter how we load the table.  Any
> ideas
> >> on
> >> what might be wrong with the bulk import to cause this problem?  We¹re
> >> thinking maybe something with the region boundaries, although they look
> ok
> >> in the GUI.
> >>
> >> Thanks for any suggestions,
> >> Adam
> >>
> >
> >
>
>


-- 
Todd Lipcon
Software Engineer, Cloudera

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