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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: reads are slow
Date Tue, 23 Feb 2010 18:06:34 GMT
the standard workaround is to change your data model to use non-super
columns instead.

supercolumns are really only for relatively small numbers of
subcolumns until 598 is addressed.

On Tue, Feb 23, 2010 at 12:01 PM, kevin <kevincastiglione@gmail.com> wrote:
> yes there is a lot more than 100. there are  around 50,000 to 100000
> columns.
>
> is there any solution for this?
>
> from the issue 598 page, i can have only 1000s of columns in a super column?
>
> On Tue, Feb 23, 2010 at 9:47 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
>>
>> how many columns total are in the supercolumn?
>>
>> if it's a lot more than 100 you are running into
>> http://issues.apache.org/jira/browse/CASSANDRA-598
>>
>> On Tue, Feb 23, 2010 at 11:44 AM, kevin <kevincastiglione@gmail.com>
>> wrote:
>> > i dont think so
>> > /dev/sdc1 is the commitlog drive, and /dev/sdd1 is the data directory.
>> >
>> > http://pastie.org/838943
>> >
>> >
>> > On Tue, Feb 23, 2010 at 9:35 AM, Jonathan Ellis <jbellis@gmail.com>
>> > wrote:
>> >>
>> >> are you i/o bound?
>> >> http://spyced.blogspot.com/2010/01/linux-performance-basics.html
>> >>
>> >> On Tue, Feb 23, 2010 at 11:33 AM, kevin <kevincastiglione@gmail.com>
>> >> wrote:
>> >> > to load 100 columns of a super column it takes over a second. how to
>> >> > improve
>> >> > this performance.
>> >> >
>> >> >
>> >> > i am using cassandra 0.5 version.
>> >> >
>> >> > output of nodeprobe info
>> >> > 29814395632524962303611017038378268216
>> >> > Load             : 9.18 GB
>> >> > Generation No    : 1266945238
>> >> > Uptime (seconds) : 638131
>> >> > Heap Memory (MB) : 47.55 / 10237.94
>> >> >
>> >> > the full config file is here
>> >> > http://pastie.org/838916
>> >> >
>> >> > I have given 10GB RAM in cassandra.in.sh.
>> >> >         -Xmx10G \
>> >> > i have increased KeysCachedFraction to 0.04. i have two different
>> >> > drives
>> >> > for
>> >> > commitlog and data directoy.
>> >> > i have about 3 million rows.
>> >> > what can i do to improve read speed?
>> >> > thanks a lot!
>> >> >
>> >
>> >
>
>

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