Nginx health checks

[Barry Abrahamson]

On Jun 10, 2008, at 4:56 PM, Aleksandar Lazic wrote:

> If you really use only the reverse proxy feature then I think the
> haproxy is the better choice due the follwoing aguments:
>
> 1.) http://haproxy.1wt.eu/10g.html
>
> http://haproxy.1wt.eu/download/1.3/doc/haproxy-en.txt search for
>
> 2.) 1.5) Increasing the overall processing power
> 3.) 3.1) Server monitoring
> 4.) 3.4) Limiting the number of concurrent sessions on each server

Thanks for pointing these out.  I was looking for #2 when I did my  
testing, but couldn't find it.  That may change my mind about  
performance.

> Some of this features would be also very nice in nginx ;-)

I am mostly interested in "3.) 3.1) Server monitoring" at this point.   
The first one is already supported, and although the last one, in  
theory, would be nice, since we use round robin for most of our load  
distribution and have enough backends, the law of averages says that  
the probability of one backend becoming overloaded while the others  
are under-utilized is relatively small.  The fair proxy balancer patch  
for nginx may deal with this theoretical problem better than counting  
concurrent connections anyway -- I don't know though since I haven't  
tried it.

> What I don't know is do you use the fcgi backend or the http backend?

Currently http, but may switch to fcgi at some point.

> One of the coolest / best feature of nginx is that he deliver the
> static content as fast a possible from he disc ;-))
>
> What I don't understand why you don't use this feature, due the fact
> that, as far as I understand, you deliver ALL the content thru the
> application, also the static one.

Most of our content is dynamic.  Static content is not served through  
the application.

There are a few things I really like about nginx that I don't find in  
HAProxy --

1) SSL -- no need for stunnel or something else to do the SSL  
negotiation.  Our % of SSL traffic is relatively low, so for us it is  
not a bottleneck.  Maybe one day it will be...

2) It's ability to be used as a web server, which could allow us to  
standardize on a single software package.

3) Abundance of 3rd party modules which allow you to extend the  
capabilities of the software and also build a community.

> As you can see I haven't setuped a blog with wordpress.

You should :)

Thanks for the feedback, it is much appreciated!

--
Barry Abrahamson | Systems Wrangler | Automattic
Blog: http://barry.wordpress.com