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From Derek Williams <de...@fyrie.net>
Subject Re: cfhistograms
Date Mon, 25 Mar 2013 17:37:04 GMT
On Mon, Mar 25, 2013 at 10:36 AM, Brian Tarbox <tarbox@cabotresearch.com>wrote:

> I think we all go through this learning curve.  Here is the answer I gave
> last time this question was asked:
>
> The output of this command seems to make no sense unless I think of it as
> 5 completely separate histograms that just happen to be displayed
> together.
>
> Using this example output should I read it as: my reads all took either 1
> or 2 sstable.  And separately, I had write latencies of 3,7,19.  And
> separately I had read latencies of 2, 8,69, etc?
>

Little correction: The actual value is in the Offset column, all the other
columns are the count for that bucket of the histogram. For example in
write latency the 3, 7, and 19 refer to how many requests had that latency.
3 write requests took 17us, 7 requests took 20us, and 19 took 24us.

-- 
Derek Williams

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