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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: WARN [Memtable] live ratio
Date Fri, 03 Feb 2012 15:32:14 GMT
It's a warn because it's nonsense for the JVM to report that an column
+ overhead, takes less space than just the column data itself.

On Tue, Jan 31, 2012 at 9:41 PM, Mohit Anchlia <mohitanchlia@gmail.com> wrote:
> I guess this is not really a WARN in that case.
>
> On Tue, Jan 31, 2012 at 4:29 PM, aaron morton <aaron@thelastpickle.com> wrote:
>> The ratio is the ratio of serialised bytes for a memtable to actual JVM
>> allocated memory. Using a ratio below 1 would imply the JVM is using less
>> bytes to store the memtable in memory than it takes to store it on disk
>> (without compression).
>>
>> The ceiling for the ratio is 64.
>>
>> The ratio is calculated periodically so if the workload changes, such as
>> system start up, the number will lag behind. I would guess numbers less than
>> 1 mean the memtable does not have any data.
>>
>> Cheers
>>
>> -----------------
>> Aaron Morton
>> Freelance Developer
>> @aaronmorton
>> http://www.thelastpickle.com
>>
>> On 1/02/2012, at 8:27 AM, Radim Kolar wrote:
>>
>>
>>  but a ration of<  1 may occur
>>
>> for column families with  a very high update to insert ratio.
>>
>> better to ask why minimum ratio is 1.0. What harm can be done with using <
>> 1.0 ratio?
>>
>>



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

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