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From aaron morton <aa...@thelastpickle.com>
Subject Re: Estimation of memtable size are wrong
Date Mon, 26 Mar 2012 17:38:53 GMT
> Yes i noticed that. Its not too often, about 1 times per week.
The assumption would be that the workload stabilises over time.

> INFO [MemoryMeter:1] 2012-03-23 00:00:18,407 Memtable.java (line 186) CFS(Keyspace='whois',
ColumnFamily='ipbans') liveRatio is 64.0 (just-counted was 16.354632747474547).  calculation
took 611ms for 8287 columns
Duh, forgot about the 25% fudge factor. 64 * 1.25 = 80. 

It's working as intended. The serialised bytes is the total throughput, which includes overwrites.


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

On 26/03/2012, at 9:11 PM, Radim Kolar wrote:

> Dne 26.3.2012 0:36, aaron morton napsal(a):
>>> 1. its not possible to run them more often? There should be some limit - run
live/serialized calculation at least once per hour. They took just few seconds.
>> The live ratio is updated every time the operation count (since startup) for the
CF doubles.
> Yes i noticed that. Its not too often, about 1 times per week.
> 
>> The ratio here is a strange 105363280 100.48 MB /  1317041 / 1.26 Mb  = 80. The live
ratio is capped at 64.
>> Can you see any log messages about the live ratio for this CF ?
> 
> Last report from problematic CF:
> INFO [MemoryMeter:1] 2012-03-23 00:00:18,407 Memtable.java (line 186) CFS(Keyspace='whois',
ColumnFamily='ipbans') liveRatio is 64.0 (just-counted was 16.354632747474547).  calculation
took 611ms for 8287 columns


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