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From aaron morton <aa...@thelastpickle.com>
Subject Re:
Date Mon, 01 Oct 2012 00:17:48 GMT
> I still don't see it in jconsole.
It's part of the CF definition. 

Check the docs for CLI or CQL which ever you are using. 

> how long would you expect to cost to read a column family of 150000 rows if it fits into
row cache entirely? It takes me around 7s now
Assuming you are talking about the client side timing for reading 150,000 rows with several
columns each this does not sound too crazy. 

Check the server side timing by calling nodetool cfstats before and after the query, the recent
stats will be be since the last time cfstats was called. 

Cheers

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

On 27/09/2012, at 2:32 PM, Manu Zhang <owenzhang1990@gmail.com> wrote:

> I still don't see it in jconsole. BTW, how long would you expect to cost to read a column
family of 150000 rows if it fits into row cache entirely? It takes me around 7s now. My experiment
is done on a single node.
> 
> On Thu, Sep 27, 2012 at 6:00 AM, aaron morton <aaron@thelastpickle.com> wrote:
> Set the caching strategy for the CF to be ROWS_ONLY.
> 
> Cheers
> 
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 26/09/2012, at 2:18 PM, Manu Zhang <owenzhang1990@gmail.com> wrote:
> 
>> The DEFAULT_CACHING_STRATEGY is Caching.KEYS_ONLY but even configuring row cache
size to be greater zero 
>>  won't enable row cache. Why? 
>> 
>> On Wed, Sep 26, 2012 at 9:44 AM, Manu Zhang <owenzhang1990@gmail.com> wrote:
>> I wonder now if "get_range_slices" call will ever look for data in row cache. I don't
see it in the codebase. Only the "get" call will check row cache?
>> 
>> 
>> On Wed, Sep 26, 2012 at 12:11 AM, Charles Brophy <cbrophy@zulily.com> wrote:
>> There are settings in cassandra.yaml that will _gradually_ reduce the available cache
to zero if you are under constant memory pressure:
>> 
>>  # Set to 1.0 to disable.  <snip>
>> reduce_cache_sizes_at: *
>> reduce_cache_capacity_to: *
>> 
>> My experience is that the cache size will not return to the configured size until
a service restart if you leave this enabled.  The text of this setting is not explicit about
the long-term cache shrinkage, so it's easy to think that it will restore the cache to its
configured size after the pressures have subsided. It won't. 
>> 
>> Charles
>> 
>> On Tue, Sep 25, 2012 at 8:14 AM, Manu Zhang <owenzhang1990@gmail.com> wrote:
>> I've enabled row cache and set its capacity to 10MB but when I check its size in
jconsole it's always 0. Isn't it that a row will be written to row cache if it isn't there
when I read the row? I've bulk loaded the data into disk so row cache is crucial to the performance.
>> 
>> 
>> 
> 
> 


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