cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mark Schnitzius <mark.schnitz...@cxense.com>
Subject Re: Feeding in specific Cassandra columns into Hadoop
Date Tue, 04 May 2010 01:15:27 GMT
If I take the exact same SlicePredicate that fails in the Hadoop example,
and pass it in to a multiget_slice, the data is returned successfully.  So
it appears the problem does lie somewhere in the tie-in to Hadoop.

I will try to create a maximally-trimmed-down example that's complete enough
to run on its own that demonstrates the failure, and will post here.  I was
just hoping that there might've been an easy fix recognizable from my
description before I had to resort to that...


Thanks
Mark


On Tue, May 4, 2010 at 1:40 AM, Jonathan Ellis <jbellis@gmail.com> wrote:

> Can you reproduce outside the Hadoop environment, i.e. w/ Thrift code?
>
> On Mon, May 3, 2010 at 5:49 AM, Mark Schnitzius
> <mark.schnitzius@cxense.com> wrote:
> > Hi all...  I am trying to feed a specific list of Cassandra column names
> in
> > as input to a Hadoop process, but for some reason it only feeds in some
> of
> > the columns I specify, not all.
> > This is a short description of the problem - I'll see if anyone might
> have
> > some insight before I dump a big load of code on you...
> > 1.  I've uploaded a bunch of data into Cassandra; the column names as
> longs
> > (dates, basically) converted to byte[8].
> > 2.  I can successfully set a SlicePredicate using setSlice_range to
> return
> > all the data for a set of columns.
> > 3.  However, if I instead call setColumn_names on the SlicePredicate,
> only
> > some of the specified columns get fed into Hadoop.
> > 4.  This faulty behavior is repeatable, with the same columns going
> missing
> > each time for the same input parameters.
> > 5.  For the values that fail, I've made fairly certain that the value for
> > the column name is getting inserted successfully, and that the exact same
> > column name is specified in the call to setColumn_names.
> > Any clues?
> >
> > AdTHANKSvance,
> > Mark
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com
>

Mime
View raw message