Weblog

I made some other web server points over at Joyeur

It’s here and it’s primarily about putting a web server in the context of the network stack and connection (with a hat tip to an old post from Querna that’s been sitting in the brain for nearly a year).

·:· Posted 17 April 2006, 23:37 by Jason Hoffman to Web servers  |  Got something to say?

Beware the trailing slash in Apache's proxy balancer

This is correct


ProxyPass / balancer://app
<Proxy balancer://app>
BalancerMember http://10.0.0.166:8181
BalancerMember http://10.0.0.166:8182
BalancerMember http://10.0.0.166:8183
BalancerMember http://10.0.0.166:8184
BalancerMember http://10.0.0.166:8185
BalancerMember http://10.0.0.166:8186
BalancerMember http://10.0.0.166:8187
BalancerMember http://10.0.0.166:8188
BalancerMember http://10.0.0.166:8189
BalancerMember http://10.0.0.166:8190
</Proxy>

This is not


ProxyPass / balancer://app
<Proxy balancer://app>
BalancerMember http://10.0.0.166:8181/
BalancerMember http://10.0.0.166:8182/
BalancerMember http://10.0.0.166:8183/
BalancerMember http://10.0.0.166:8184/
BalancerMember http://10.0.0.166:8185/
BalancerMember http://10.0.0.166:8186/
BalancerMember http://10.0.0.166:8187/
BalancerMember http://10.0.0.166:8188/
BalancerMember http://10.0.0.166:8189/
BalancerMember http://10.0.0.166:8190/
</Proxy>

This is also not correct


ProxyPass / balancer://app/
<Proxy balancer://app/>
BalancerMember http://10.0.0.166:8181/
BalancerMember http://10.0.0.166:8182/
BalancerMember http://10.0.0.166:8183/
BalancerMember http://10.0.0.166:8184/
BalancerMember http://10.0.0.166:8185/
</Proxy>
Made purty over there

And this is neat

Apache 2.2 Load Balancer Manager

·:· Posted 17 April 2006, 22:50 by Jason Hoffman to Web servers  |  Got something to say? [2]

What about Apache to Mongrel for Rails applications?

Just earlier I compared our lighttpd and litespeed serving up one of our Rails applications by proxying to mongrel

So what about Apache 2 using the prefork MPM?

This is our vanilla (and fat) Apache 2.0.x install.

Server Hostname: mongrel-ap.textdrive.com
Server Port: 80
Concurrency Level: 100
Complete requests: 10000
Requests per second: 431.57 [#/sec] (mean)

By fat, I mean this thing does mod_security, php, fcgi, DAV, SVN and has other authentication modules for MySQL and IMAP.

Let’s turn some stuff off

Let’s do a couple of things: let’s turn off mod_security as an input filter and let’s set KeepAlive Off

Server Hostname: mongrel-ap.textdrive.com
Server Port: 80
Concurrency Level: 100
Complete requests: 10000
Requests per second: 904.47 [#/sec] (mean)

Let’s start up more servers since we’re hitting it with a concurrency of 100

Was


<IfModule prefork.c>
StartServers 30
MinSpareServers 30
MaxSpareServers 55
ServerLimit 600
MaxClients 400
MaxRequestsPerChild 2500
ListenBacklog 1000
</IfModule>

Now


<IfModule prefork.c>
StartServers 100
MinSpareServers 10
MaxSpareServers 10
ServerLimit 10000
MaxClients 10000
MaxRequestsPerChild 2500
ListenBacklog 1000
</IfModule>

Server Hostname: mongrel-ap.textdrive.com
Server Port: 80
Concurrency Level: 100
Complete requests: 10000
Requests per second: 882.98 [#/sec] (mean)

Not too much of a change.

Let’s add some stuff

EnableSendfile On
EnableMMAP On

Server Hostname: mongrel-ap.textdrive.com
Server Port: 80
Concurrency Level: 100
Complete requests: 10000
Requests per second: 982.27 [#/sec] (mean)

OK that’s the best so far.

Hmm … what else can I do with this (without turning off our SVN, DAV etc)

Ah, I’ll turn off .htaccess and input filtering by mod_deflate as well

Server Hostname: mongrel-ap.textdrive.com
Server Port: 80
Concurrency Level: 100
Complete requests: 10000
Requests per second: 1070.59 [#/sec] (mean)

But I’ll turn those back on, no biggie.

The biggest hit actually comes from mod_security, restoring it after all the other changes pushed it back down to about 500 requests/second.

And this is very respectable by the way considering that just did a little better than lighttpd and litespeed for proxying to mongrel.

Joyent.com is a little PHP (mod_php) site with no database backend and under the same conditions it does

Requests per second: 588.36 [#/sec] (mean)

And the other and last point is that this is still a slow Apache because it’s prefork on FreeBSD and still doing rewrites, DAV, SVN and has several third party auth modules. I’m certain that it’s performance can be taken up several fold with a slim and trim proxy-only Apache 2.2 instance using the worker or event MPM.

There is also now a load-balancing extension for mod_proxy in Apache 2.2

There also wasn’t an appreciable load difference when using Apache and it’s nice to see the same mongrel processes stay at ~28MB (I used the same exact mongrel process with 4 threads for apache, lighttpd and litespeed).

·:· Posted 17 April 2006, 02:27 by Jason Hoffman to Rails  |  Got something to say? [3]

Lighttpd versus Litespeed with Mongrel as a backend for Rails applications

Done like always: client -> server over a gigabit connection, and both lighttpd and litespeed are proxying back to the same set of mongrel processes (in other words everything is exactly matched including file size and transfer rates).

This set is on FreeBSD with a ruby compile that has no pthreads.

Litespeed Enterprise 2.1.14 -> Mongrel 0.3.12.4

Concurrency Level: 100
Requests per second: 1008.04 [#/sec] (mean)

Lighttpd 1.4.10 -> Mongrel 0.3.12.4

Concurrency Level: 100
Requests per second: 1010.36 [#/sec] (mean)

This is forcing everything to be served through mongrel, and was perfectly comparable with fastcgi’s performance. Having the file be cached to the filesystem by rails and served as a static file by litespeed or via lighttpd’s mod_cml actually boosts it another 3-4 fold.

So …?

  1. Mongrel is good stuff.
  2. Lighttpd or litespeed for the simple purposes of being a load-balancing proxy capable of virtual hosting? Doesn’t matter, they’re comparable.

BTW, if you want to click around to the public sites, http://mongrel.textdrive.com and http://mongrel-lite.textdrive.com

·:· Posted 16 April 2006, 23:16 by Jason Hoffman to Rails  |  Got something to say? [1]

Watch Out for Software Updates

Administrating a shared server is not the easiest thing to do. Half of the customers want to live on the bleeding edge and demand every new version of software to be installed right away. The other half is maybe running a commercial website and therefore more conservative regarding updates: “Do not ever upgrade X to the new version, it will break my site and will cost me millions of $”, they say slightly exaggerating.

So, what to do? We at TextDrive lean a bit to the bleeding edge side, but of course also care about more conservative customers. We are trying to find a way in between and most importantly give a heads up before we do major updates.

We installed a RSS feed for software updates and I recommend subscribing to it right now:

It will be used as the main communication channel for software updates. We will announce upcoming major software updates there and inform you when we did a smaller upgrade.

Next week, two big updates are coming:

·:· Posted 15 April 2006, 12:55 by Florian Munz to Web servers  |  Got something to say? [1]

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