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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: WARN [Memtable] live ratio
Date Fri, 03 Feb 2012 16:46:35 GMT
You should come up with a way to reproduce so we can fix it. :)

On Fri, Feb 3, 2012 at 10:31 AM, Mohit Anchlia <mohitanchlia@gmail.com> wrote:
> On Fri, Feb 3, 2012 at 7:32 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
>> 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.
>>
>
> But is there any action we need to take, or worry about? We trigger
> alerts based on WARN and ERROR. But if there is nothing to do then it
> probably is just an INFO.
>> 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



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

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