Quad Opterons + FreeBSD + Lighttpd + FastCGI/PHP + APC = Fast vB :)

Yup, I migrated my forums to new servers (dual xeon to quad opterons) using completely new software - FreeBSD, Lighttpd instead of Apache. Lighttpd is really amazing, and I recommend that everyone switch from Apache to Lighttpd. APC works fine on the setup too. Just sharing.

[Zachery]

Originally Posted by adalren

What kind of problems are you having with lighttpd?

We're using lighttpd + phpfcgi + 64bit CentOS and lately experiencing segfaults from the php processes. I see a few bug listings regarding segfaults on APC and have a hunch it might be that.

BTW, eA does not work on a 64bit OS.

I think it was digitalpoint on vB.com who commented about segfaults and APC under high load.

[Dan]

I've had a recent experience with FreeBSD servers and Erwin is right, it's really a good distro to use.

But with Lighttpd reference I haven't really had a chance to play with it much in a production enviroment, I'm currently playing around with it on my localhost. Hopefully one day my host can switch it or I could get my own server and use it.

[Erwin]

Ahhh... eA doesn't work with 64bit... didn't know that... that explains it.

[adalren]

Originally Posted by Zachery

I think it was digitalpoint on vB.com who commented about segfaults and APC under high load.

That can't be the case since the load is < 1. It seems like a child php process segfaults and serves error pages until the parent process kills it after the # of PHP_FCGI_MAX_REQUESTS. At least it recovers.

[Erwin]

Anyone want to share their lighttpd.conf? I can't use the quake.net one as my server crashes with it (server 500 error).

I'll share the tweaks I've made to mine:

Add these lines to the top:

server.max-keep-alive-requests = 0
server.max-fds = 2048
server.stat-cache-engine = "fam"


Basically, switch off keep-alive (well, it helps to speed things up on my webserver), double the maxed opened files from 1024 to 2048 (if you have a busy server) and use the stat cache system.

It seems to work well for me so far - let's see how it goes at peak times (it's off-peak now, only 1,000 users online).

More info on optimizing lighttpd here:

http://www.lighttpd.net/documentation/performance.html

[kmike]

Hmm, keep alive should help multiplexing web servers like lighttpd. Number of open files should not be an issue if you're not on the shared hosting, and there're no other downsides to enabling keep-alive.

[adalren]

How do you get fam/gamin to work? I installed gamin (yum install gamin) and there wasn't any daemons or init scripts to run.

Here is my conf file. It runs fine with apc 3.0.8 but segfaults with 3.0.10.

server.event-handler = "linux-sysepoll"
server.max-fds = 4096
server.max-keep-alive-requests = 4
server.max-keep-alive-idle = 4
server.max-read-idle = 20
server.max-write-idle = 180

[Erwin]

Originally Posted by kmike

Hmm, keep alive should help multiplexing web servers like lighttpd. Number of open files should not be an issue if you're not on the shared hosting, and there're no other downsides to enabling keep-alive.

I thought keep alive is only useful for static files? I may be wrong obviously, I'm no expert. No. of files may be significant if there are lot of attachments, again from what I've read, so it's probably more relevant for an attachment server. Enabling keep-alive just means connections are kept longer - I have to say that when I was using apache, I never had keep alive on, even with my image server.

[kmike]

Well, I'm going to get to the basics on that.
The beauty of multiplexed web servers (lighttpd, thttpd, Zeus, nginx, etc) is in that number of connections isn't a choke point, their performance is usually disk (for static file serving) or CPU (for dynamic content) bound.
So there's _no_ reason not to enable keep-alive as it eliminates the need to re-open connection for the next request(s), and managing idle connections does not take up any resources for a multiplexed web server utilizing one of the advanced solutions to c10K problem like epoll, rtsig or kqueue.

Back to Apache, everyone's disabling keep-alive in Apache because every connection, even an idle one, requires one active Apache process or thread to manage it, taking up memory.

I hope it answers your questions.

[Erwin]

For some reason, the default

server.max-write-idle = 360

is too short... I've increased that to 720 and it's still too slow according to the error log.

I'll give:

server.max-keep-alive-requests = 4
server.max-keep-alive-idle = 4

a try then. I'll report back.

In relation to kqueue, I'm using FreeBSD so I have this line:

server.event-handler = "freebsd-kqueue"

That covers that yeah?