Using replace module before nginx store cache.

kroptgye · 2013-07-19T11:07:13+00:00

Hi,agentzh: I am glad to announce that the new development version of ngx_openresty, 1.4.1.1, is now released: http://openresty.org/#Downl...

Using replace module before nginx store cache.

kroptgye

So as you(agentzh) say i try to play with your module https://github.com/agentzh/replace-filter-nginx-module.

He is pretty fast but…

I made some test on my vm;

So what we have.

With test filter.

location = / {
proxy_pass http://1k-loud-lods.tk/; #My test site Joomla with default template.
proxy_set_header Accept-Encoding "";
proxy_ignore_headers Expires Cache-Control;
proxy_cache STATIC;
proxy_cache_valid 200 302 60m;
proxy_cache_valid 404 1m;
replace_filter '<script\b[^>]*>([\s\S]*?)<\/script>|\s\s+|\t|\n' '' 'ig'; #Test Filter
}

$ ab -n 1000 -c10 http://192.168.56.10/

I have:

Server Software: ngx_openresty/1.2.8.6
Server Hostname: 192.168.56.10
Server Port: 80
Document Path: /
Document Length: 11918 bytes
Concurrency Level: 10
Time taken for tests: 2.446 seconds
Complete requests: 1000
Failed requests: 0
Write errors: 0
Total transferred: 12212000 bytes
HTML transferred: 11918000 bytes
Requests per second: 408.80 [#/sec] (mean)
Time per request: 24.462 [ms] (mean)
Time per request: 2.446 [ms] (mean, across all concurrent requests)
Transfer rate: 4875.30 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.3 0 3
Processing: 3 24 4.0 23 46
Waiting: 0 24 3.9 23 46
Total: 4 24 3.9 23 46
Percentage of the requests served within a certain time (ms)
50% 23
66% 25
75% 26
80% 27
90% 28
95% 31
98% 34
99% 41
100% 46 (longest request)

And without, yeah faster but how much?

Server Software: ngx_openresty/1.2.8.6
Server Hostname: 192.168.56.10
Server Port: 80
Document Path: /
Document Length: 16401 bytes
Concurrency Level: 10
Time taken for tests: 0.187 seconds
Complete requests: 1000
Failed requests: 0
Write errors: 0
Total transferred: 16695000 bytes
HTML transferred: 16401000 bytes
Requests per second: 5356.62 [#/sec] (mean) That much.
Time per request: 1.867 [ms] (mean)
Time per request: 0.187 [ms] (mean, across all concurrent requests)
Transfer rate: 87332.73 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.3 0 1
Processing: 0 2 0.6 1 6
Waiting: 0 1 0.7 1 5
Total: 1 2 0.6 2 6
WARNING: The median and mean for the processing time are not within a normal deviation
These results are probably not that reliable.
Percentage of the requests served within a certain time (ms)
50% 2
66% 2
75% 2
80% 2
90% 2
95% 3
98% 3
99% 4
100% 6 (longest request)

So use regexp even from «god of optimization»(agentzh) is very expensive.

And that's why i think, there must be method to use filter before nginx store cache on disk, singletime.(hook proxy_cache?)

I mean call regexp single time on update cache not every request, process cached version.

That i think must save speed of direct cache and flexibility of filters.

P/s Those test very inaccurate just to show difference.

P.p.s Fast(i just image that) and wrong(?) solution i guess is something like:

location = /cached {

proxy_pass http://1k-loud-lods.tk/; #My Test Site

proxy_set_header Accept-Encoding "";

proxy_ignore_headers Expires Cache-Control;

replace_filter '<script\b[^>]*>([\s\S]*?)<\/script>|\s\s+|\t|\n' '' 'ig';

}

location = / {

proxy_pass http://192.168.56.10/cached;#path to itself

proxy_set_header Accept-Encoding "";

proxy_ignore_headers Expires Cache-Control;

proxy_cache STATIC;

proxy_cache_valid 200 302 60m;

proxy_cache_valid 404 1m;

}

And yeah than its store in cache filtered version and bench say 5274.79 [#/sec] (mean) , but its ugly and you can create better solution.:)

Thanks for your time.

Best regards. Viktor.M

agentzh

Hello!

On Thu, Jul 18, 2013 at 8:07 PM, Viktor malezink wrote:
> So as you(agentzh) say i try to play with your module
> https://github.com/agentzh/replace-filter-nginx-module.
> He is pretty fast but…
>
[...]
> So use regexp even from «god of optimization»(agentzh)  is very expensive.
> in b4(Sure captain obvious its expensive, text analyze is very expensive and
> cache will faster coz it's cache moron).
>

First of all, thank you for trying ngx_replace_filter and sregex!

The slowness you're seeing comes from the unoptimized sregex library.
You can confirm this by rendering a C-land flamegraph for your busiest
nginx worker process by running the ngx-sample-bt tool if you're on
Linux:

    https://github.com/agentzh/nginx-systemtap-toolkit#ngx-sample-bt

I must appologize for that because I haven't done many important regex
optimizations in my sregex engine. It's on my TODO list :)

> And that's why i think, there must be method to use filter before nginx
> store cache on disk, singletime.(hook proxy_cache?)
> I mean call regexp single time on update cache not every request, process
> cached version.
> That i think must save speed of direct cache and flexibility of filters.
>

Well, I think you'll probably have to patch the nginx core for this
because there's no hooks available for external nginx modules AFAIK.

> P/s Those test very inaccurate just to show difference.
>
> P.p.s Fast(i just image that) and wrong(?) solution i guess is something
> like:
> location = /cached {
>             proxy_pass http://1k-loud-lods.tk/; #My Test Site
>             proxy_set_header Accept-Encoding "";
>             proxy_ignore_headers Expires Cache-Control;
>             replace_filter '<script\b[^>]*>([\s\S]*?)<\/script>|\s\s+|\t|\n'
> '' 'ig';
>         }
> location = / {
>     proxy_pass http://192.168.56.10/cached;#path to itself
>     proxy_set_header Accept-Encoding "";
>     proxy_ignore_headers Expires Cache-Control;
>     proxy_cache STATIC;
>     proxy_cache_valid  200 302  60m;
>     proxy_cache_valid  404      1m;
> }
> And yeah than its store in cache filtered version and bench say 5274.79
> [#/sec] (mean) , but its ugly and you can create better solution.:)

Yeah, you could do something like this though it's just a bit more
expensive than hooking proxy_cache (as you've already seen) :)

Best regards,
-agentzh