> Its in the order of 261 to 8000 and the ratio is 0.00. But i guess 8000 is 
> bit high. Is there a way to fix/improve it?
Sorry I don't understand what you mean. But if the ratio is 0.0 all is good. 

Could you include the full output from cfstats for the CF you are looking at ?

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 15/02/2012, at 1:00 PM, Eran Chinthaka Withana wrote:

> Its in the order of 261 to 8000 and the ratio is 0.00. But i guess 8000 is 
> bit high. Is there a way to fix/improve it?
> 
> Thanks,
> Eran Chinthaka Withana
> 
> 
> On Tue, Feb 14, 2012 at 3:42 PM, aaron morton <aa...@thelastpickle.com> wrote:
> Out of interest what does cfstats say about the bloom filter stats ? A high 
> false positive could lead to a low key cache hit rate.
> 
>> Also, is there a way to warm start the key cache, meaning pre-load the 
>> amount of keys I set as keys_cached?
> 
> See key_cache_save_period when creating the CF.
> 
> Cheers
> 
> 
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 15/02/2012, at 5:54 AM, Eran Chinthaka Withana wrote:
> 
>> Hi,
>> 
>> I'm using Cassandra 1.0.7 and I've set the keys_cached to about 80% (using 
>> the numerical values). This is visible in cfstats too. But I'm getting less 
>> than 20% (or sometimes even 0%) key cache hit rate. Well, the data access 
>> pattern is not the issue here as I know they are retrieving the same row 
>> multiple times. I'm using hector client with dynamic load balancing policy 
>> with consistency ONE for both reads and writes. Any ideas on how to find the 
>> issue and fix this?
>> 
>> Here is what I see on cfstats.
>> 
>> Key cache capacity: 16637958
>> Key cache size: 16637958
>> Key cache hit rate: 0.045454545454545456
>> 
>> Also, is there a way to warm start the key cache, meaning pre-load the 
>> amount of keys I set as keys_cached?
>> 
>> Thanks,
>> Eran
> 
> 

Reply via email to