cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Brandon Williams <>
Subject Re: row cache vs frequent row updates vs write through row cache
Date Fri, 05 Nov 2010 18:49:38 GMT
On Fri, Nov 5, 2010 at 1:41 PM, Jeremy Davis

> I saw in the Riptano "Tuning Cassandra" slide deck that the row cache can
> be detrimental if there are a lot of updates to the cached row. Is this
> because the cache is not write through, and every update necessitates
> creation of a new row?
> I see there is an open issue:
>  for implementing
> write through in 0.8.

The problem is that if the row is being updated a lot, the cache is turning
over quickly, and this exerts GC pressure on the JVM.  Even if it were
write-through, row cache is probably a bad match for this kind of row, it's
much better at mostly static rows.  Rely on keycache and OS file cache for
these instead.


View raw message