Subject: Header Stats

From: James M Snell <[email-masked]>
Date: Tue, 22 Jan 2013 13:24:14 -0800

I've started working on generating stats for individual headers within
messages. Rather than take up too much space here on the list for the
results, I am keeping the results in my github fork [1] of the
compression-test code and will be posting summaries of the results
periodically on my personal blog [2]. I will be putting together a summary
of my findings together in time for the interim meeting next week.
Unfortunately, however, I will not be able to attend the meeting.

[1] https://github.com/jasnell/compression-test/blob/master/counts/
[2] http://chmod777self.blogspot.com/2013/01/http-20-header-stats.html

- James

---

From: James M Snell <[email-masked]>
Date: Tue, 22 Jan 2013 20:33:50 -0800

Ok.. I have updated the calculations to show:

  1. General variability of header values. The lower the number, the more
redundant the value tends to be.
  2. A frequency distribution of specific values per header. This is rather
verbose but extremely informative
  3. For date and numeric header values, comparison values between the
text-value and optimized binary encoding value.
  4. A summation of the total bytes saved by using the optimized binary
encoding for dates and numeric headers.

TODO:

  - Implement experimental Set-Cookie, Cookie and Cache-Control headers to
see the difference for binary encoding
  - Properly handle null-separated value lists

If there are other interesting calculations you'd like to see, let me
know...

The updated output is here:
https://github.com/jasnell/compression-test/tree/master/counts

---

From: RUELLAN Herve <[email-masked]>
Date: Wed, 23 Jan 2013 08:55:37 +0000

James,

This is interesting and useful information.

A few suggestions:
- Sorting the header names would help finding them.
- Possibly also sorting the header values, either alphabetically or by frequency.
- The "ratio" for encoded values seems to be the percentage of size reduction, maybe rename the line.
- Adding the explanations from your email directly in the files would help understanding them.

Hervé.

> -----Original Message-----
> From: James M Snell [mailto:[email-masked]]
> Sent: mercredi 23 janvier 2013 05:34
> To: [email-masked]
> Subject: Re: Header Stats
> 
>   - Implement experimental Set-Cookie, Cookie and Cache-Control headers
> to see the difference for binary encoding
> If there are other interesting calculations you'd like to see, let me know...
> 
> 
> The updated output is here: https://github.com/jasnell/compression-
> test/tree/master/counts
> 
> 
> results, I am keeping the results in my github fork [1] of the compression-test
> code and will be posting summaries of the results periodically on my personal
> blog [2]. I will be putting together a summary of my findings together in time
> for the interim meeting next week. Unfortunately, however, I will not be
> able to attend the meeting.
> 
>