Re: [RFC] byte hit ratio

On 02/06/2012 06:01 PM, Amos Jeffries wrote:
> We have a long history of questions and bugs mentioning negative numbers
> in the byte hit ratio.
>
> I've always thought it was a bug we had not tracked down, but the FAQ
> says it is correct.
> http://wiki.squid-cache.org/SquidFaq/InnerWorkings#Why_do_I_see_negative_byte_hit_ratio.3F
>
>
> I've discussed this with a professional statistician I work with and she
> agrees the algorithm is not calculating hit ratio as per our definition
> of what a HIT is. What is does seem to be calculating is a net traffic
> GAIN ratio.

The definition of a document hit differs from a definition of a byte
hit. I agree that the term "byte hit ratio" (and the concept of a byte
hit itself) is probably worse than "bandwidth saving/loss", "bandwidth
gain/loss" or some other term we can come up with (I would not use
"traffic gain" nor would I make negative numbers desirable).

> What I propose is make the numbers reported as HIT ratios use the same
> algorithm. The current request ratio one. And to add alongside this a
> record for Gain/Loss Ratio as output by this byte calculation.

I do not think we should change how bandwidth gain/loss is computed (at
least I would need to see the actual change first). We can change the
label used for that number.

HTH,

Alex.
Received on Tue Feb 07 2012 - 18:35:24 MST