cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Saket Joshi" <sjo...@touchcommerce.com>
Subject RE: cassandra row cache
Date Thu, 13 Jan 2011 19:05:02 GMT
Yes it does change. 

-----Original Message-----
From: Jonathan Ellis [mailto:jbellis@gmail.com] 
Sent: Thursday, January 13, 2011 11:01 AM
To: user
Subject: Re: cassandra row cache

does the cache size change between 2nd and 3rd time?

On Thu, Jan 13, 2011 at 10:47 AM, Saket Joshi <sjoshi@touchcommerce.com>
wrote:
> Hi,
>
> I am running a 15 node cluster ,version 0.6.8, Linux 64bit OS, using
mmap
> I/O, 6GB ram allocated. I have row cache enabled to 80000 keys (mean
row
> size is 2KB). I am observing a strange behaviour.. I query for 1.6
Million
> rows across the cluster and time taken is around 40 mins , I query the
same
> data again , the time now is 25 mins to fetch data (i am expecting the
cache
> to be warm now) , but i see row cache hit rate around 30% . Now i
request
> the same data 3rd time, time to fetch is under 4 mins and cache hit
ratios
> are 99% ... Does any one have an idea why this may be happening ?
>
>
>
>
>
> Thanks,
>
> Saket



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com

Mime
View raw message