Gzip and Slimmer optimization anecdote
30 January 2007
mod_gzip is out of the question because as far as I've understood it it does a compression on the fly, every time you request the file.
Other solutions have disappointed me because enabling gzip compression has been for all content. I don't want my HTML files gzipped because they're rendered on the fly based on business logic plus by compressing the HTML files. Long story short my yet-to-be-released app now serves the following files from Zope but are only compressed and whitespace slimmed once per server restart:
FILE ORIG SIZE NEW SIZE REDUCTION screen.css 15224 2738 556% print.css 2633 885 298% jquery-latest.js* 57712 18130 318% jquery-latest.pack.js 20461 10513 195% common.js 3803 1131 336% complete-expense.js 18184 2847 639% Total 118017 36244 326% * only used in debug mode
Yes that's right. The static files are now 326% smaller in file size and since the complexity is
O(1) the CPU overhead is virtually none. What's cool about this is as an application developer I don't have to worry about it once the files have been set on the class. I never actually see the slimmed or compressed files. The code is also clever enough to serve the uncompressed version of the file if the server doesn't accept gzip using
To make things even more optimized; add the fact that I'm running this Zope behind Squid and with this command:
# nice -n 20 ab2 -n1000 -c10 http://XXX/misc_/MExpenses/screen.css
I get this lovely result:
Concurrency Level: 10 Time taken for tests: 0.372630 seconds Complete requests: 1000 Failed requests: 0 Write errors: 0 Total transferred: 3168000 bytes HTML transferred: 2738000 bytes Requests per second: 2683.63 [#/sec] (mean) Time per request: 3.726 [ms] (mean) Time per request: 0.373 [ms] (mean, across all concurrent requests) Transfer rate: 8300.46 [Kbytes/sec] received
Bare in mind that this is also proxied by Apache2 to get the extra comfort that Apache2 gives us.
Doing the same benchmark on the screen.css file WITH Squid but without gzipping and slimming it I get this result:
Concurrency Level: 10 Time taken for tests: 1.471274 seconds Complete requests: 1000 Failed requests: 0 Write errors: 0 Total transferred: 15613552 bytes HTML transferred: 15224000 bytes Requests per second: 679.68 [#/sec] (mean) Time per request: 14.713 [ms] (mean) Time per request: 1.471 [ms] (mean, across all concurrent requests) Transfer rate: 10363.13 [Kbytes/sec] received
(Without Squid caching, my Zope in this instance does 242.4 [#/sec] for the same file)
Apart from making Zope does less hard work for stupid static files, I've managed to go from 242 requests per second up to 2684 requests per second. Not bad :)