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Posted to user@cassandra.apache.org by Sanjeev Kulkarni <sa...@locomatix.com> on 2011/09/29 07:03:29 UTC
nodetools cfstats question
Hey guys,
I'm using a three node cluster running 0.8.6 with rf of 3. Its a freshly
installed cluster with no upgrade history.
I have 6 cfs and only one of them is written into. That cf has around one
thousand keys. A quick key_range_scan verifies this.
However when I do cfstats, I see the following for this cf.
Number of Keys (estimate): 5248
Key cache capacity: 200000
Key cache size: 99329
What is the definition of these three output values? Both the Number of Keys
and Key Cache size are way over what they should be.
Thanks!
Re: nodetools cfstats question
Posted by Jonathan Ellis <jb...@gmail.com>.
Yes, because the cache is not full so there is no pressure to remove
old entries.
On Thu, Sep 29, 2011 at 11:52 AM, Sanjeev Kulkarni
<sa...@locomatix.com> wrote:
> Hi Thamizh,
> Thanks for the answer.
> I understand the part about the Key cache capacity being 200000 which is the
> default value.
> But Key cache size being 99k? Does this represent that cassandra has
> allocated 99k for key cache even though the actual keys are far less?
>
> On Thu, Sep 29, 2011 at 3:47 AM, Thamizh <tc...@yahoo.co.in> wrote:
>>
>> please check [default@unknown] help create column family;
>> These are default values, until you explicitly mentioned on CF creation.
>>
>> Regards,
>> Thamizhannal
>> ________________________________
>> From: Sanjeev Kulkarni <sa...@locomatix.com>
>> To: user@cassandra.apache.org
>> Sent: Thursday, 29 September 2011 10:33 AM
>> Subject: nodetools cfstats question
>>
>> Hey guys,
>> I'm using a three node cluster running 0.8.6 with rf of 3. Its a freshly
>> installed cluster with no upgrade history.
>> I have 6 cfs and only one of them is written into. That cf has around one
>> thousand keys. A quick key_range_scan verifies this.
>> However when I do cfstats, I see the following for this cf.
>> Number of Keys (estimate): 5248
>> Key cache capacity: 200000
>> Key cache size: 99329
>> What is the definition of these three output values? Both the Number of
>> Keys and Key Cache size are way over what they should be.
>> Thanks!
>>
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com
Re: nodetools cfstats question
Posted by Sanjeev Kulkarni <sa...@locomatix.com>.
Hi Thamizh,
Thanks for the answer.
I understand the part about the Key cache capacity being 200000 which is the
default value.
But Key cache size being 99k? Does this represent that cassandra has
allocated 99k for key cache even though the actual keys are far less?
On Thu, Sep 29, 2011 at 3:47 AM, Thamizh <tc...@yahoo.co.in> wrote:
> please check [default@unknown] help create column family;
> These are default values, until you explicitly mentioned on CF creation.
>
> Regards,
> Thamizhannal
> ------------------------------
> *From:* Sanjeev Kulkarni <sa...@locomatix.com>
> *To:* user@cassandra.apache.org
> *Sent:* Thursday, 29 September 2011 10:33 AM
> *Subject:* nodetools cfstats question
>
> Hey guys,
> I'm using a three node cluster running 0.8.6 with rf of 3. Its a freshly
> installed cluster with no upgrade history.
> I have 6 cfs and only one of them is written into. That cf has around one
> thousand keys. A quick key_range_scan verifies this.
> However when I do cfstats, I see the following for this cf.
>
> Number of Keys (estimate): 5248
> Key cache capacity: 200000
> Key cache size: 99329
>
> What is the definition of these three output values? Both the Number of
> Keys and Key Cache size are way over what they should be.
> Thanks!
>
>
>
Re: nodetools cfstats question
Posted by Thamizh <tc...@yahoo.co.in>.
please check [default@unknown] help create column family;
These are default values, until you explicitly mentioned on CF creation.
Regards,
Thamizhannal
________________________________
From: Sanjeev Kulkarni <sa...@locomatix.com>
To: user@cassandra.apache.org
Sent: Thursday, 29 September 2011 10:33 AM
Subject: nodetools cfstats question
Hey guys,
I'm using a three node cluster running 0.8.6 with rf of 3. Its a freshly installed cluster with no upgrade history.
I have 6 cfs and only one of them is written into. That cf has around one thousand keys. A quick key_range_scan verifies this.
However when I do cfstats, I see the following for this cf.
Number of Keys (estimate): 5248
Key cache capacity: 200000
Key cache size: 99329
What is the definition of these three output values? Both the Number of Keys and Key Cache size are way over what they should be.
Thanks!