Apache Mod_Proxy or Squid?

[DVDGuy]

Hey Shri, I know you had evaluated mod_proxy and squid. Care to share the results? Want to look at a new reverse proxy setup for one of my sites.

[shri]

Currently the main proxies are run using squid in reverse caching proxy mode.

However, have been very impressed with some of the capabilities of Apache 2.2's mod_proxy. Specifically the ability to redirect to servers based on named virtual hosts / directories etc.

I'm compiling Apache with mod_proxy as we speak.

./configure --enable-proxy --enable-proxy-httpd --enable-proxy-balancer --enable-headers --enable-file-cache --enable-cache --enable-disk-cache --enable-static-htcache-clean --prefix=/usr/local/apache --with-mpm=worker

[shri]

Initial reaction after replacing a year old Squid cache... mod_proxy might not offer the best performance, but it does offer a lot of flexibility.

Also.. do keep in mind that the mod_proxy performance is within a few percentage points of Squid, so not a major issue, specially since it offers us some great flexibility.

[Steve-o]

Squid 3 as a complete rewrite is supposed to bump up the performance a bit as progress has been limited for a while. I used Squid as a convenient gateway that automagically redirects to a simple static page server when the main server fails.

Perlbal is an alternative if all you are after is a software load balancing solution.

[shri]

Steve-O : Would Squid 3 allow us to build http / url aware redirection and caching?

For a lot of the mirrors we run, we just do this for example...

ProxyPassMatch ^(/.*\.xpi)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.png)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.gif)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.zip)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.exe)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.jar)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.tar)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.asc)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.md5)$ http://127.0.0.1:81/$1
ProxyPassMatch ^(/.*\.gz)$ http://127.0.0.1:81/$1

Would Squid be able to direct say static traffic to one server (gif / jpg / css etc) and the rest to the main web server?

[shri]

Ok - Apache mod_proxy + mod_cache (mod_disk_cache) have been running on www.geoexpat.com for about 24 hours now. No problems.. infact a random issue with 403 errors getting cached seems to have been eliminated.

I definitely see us replacing a couple of other squids with mod_proxy - just because of the named virtual host capabilities.

[Steve-o]

Originally Posted by shri

Steve-O : Would Squid 3 allow us to build http / url aware redirection and caching?

Squid 2 does this with external redirectors, you can get them to do anything you want. Commonly found in some Squid A/V modules.

Caching isn't overly productive on forums, hence the Perlbal suggestion. You could expose the static web host externally, it would make things easier.

[shri]

In our case specifically on geoexpat ... we proxy out of HK, so caching css / images / javascript etc locally does make a fair bit of difference in speed for the end user.

[shri]

We found several cases where corrupted javascript / css were being delivered.

Long story short ... turns out some headers were getting messed up while transitioning from lighttpd to apache (lighty was forcing a compress on JS / CSS).

So .. if you're using apache -> lighty type proxying ... turn off the mod_deflate in there.