trying to use row_cache (b/c we have hot rows) but nodetool info says zero requests

[Brian Tarbox <ta...@cabotresearch.com>]

We have quite wide rows and do a lot of concentrated processing on each
row...so I thought I'd try the row cache on one node in my cluster to see
if I could detect an effect of using it.

The problem is that nodetool info says that even with a two gig row_cache
we're getting zero requests.  Since my client program is actively
processing, and since keycache shows lots of activity I'm puzzled.

Shouldn't any read of a column cause the entire row to be loaded?

My entire data file is only 32 gig right now so its hard to imagine the 2
gig is too small to hold even a single row?

Any suggestions how to proceed are appreciated.

Thanks.

Brian Tarbox

Re: trying to use row_cache (b/c we have hot rows) but nodetool info says zero requests

[Edward Capriolo <ed...@gmail.com>]

You have to change the column family cache info from keys_only to otherwise
the cache will not br on for this cf.

On Wednesday, January 16, 2013, Brian Tarbox <ta...@cabotresearch.com>
wrote:
> We have quite wide rows and do a lot of concentrated processing on each
row...so I thought I'd try the row cache on one node in my cluster to see
if I could detect an effect of using it.
> The problem is that nodetool info says that even with a two gig row_cache
we're getting zero requests.  Since my client program is actively
processing, and since keycache shows lots of activity I'm puzzled.
> Shouldn't any read of a column cause the entire row to be loaded?
> My entire data file is only 32 gig right now so its hard to imagine the 2
gig is too small to hold even a single row?
> Any suggestions how to proceed are appreciated.
> Thanks.
> Brian Tarbox