A few basic questions

[Stefan Caunter]

On Mon, Mar 29, 2010 at 10:47 AM, David Miller <dmil.ng1nx at metheus.org> wrote:
> Hi All;
>
> The company I work for is moving to a drupal content management system.  We
> expect to install a caching reverse proxy between the drupal servers and the
> Internet.  I'm looking into nginx and varnish for that role.

nginx is generally used to speed up php with fastcgi, good idea with drupal
varnish won't speed up server performance in the same way but will
help with scale, and is excellent when combined with nginx

>
> There's no question nginx provides for at least a basic high-speed caching
> reverse proxy, but I'd appreciate input from people using it with regards to
> these features:
>
> 1) Flexible health-checks of back-end web servers.  Can I configure nginx to
> accept a 503, for example, as an acceptable return code?  Can I specify a
> different health-check page for each back-end server?

I know varnish has configurable health checks, more relevant to see
how nginx is doing.

> 2) Flexibility in load balancing.  Can I specify anything other than
> round-robin?  Least connections, lowest load, that sort of thing?

Priority is assignable, and health checks remove servers from the pool
in varnish.

> 3) Ability to purge or invalidate selected pages.  For example, a user logs
> in and updates a page that's currently cached.  Can I remove/overwrite that
> particular page in an nginx caching proxy?

nginx and varnish update on any change; varnish can be set to cache
longer to delay updates, not sure about nginx.

> 4) Any other words of wisdom regarding nginx vs varnish?

nginx is a better server; it will run your php app the best. varnish
is a better cache to override server settings and direct client
browsers better.

Stef

---
Stefan Caunter
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Skype: stefan.caunter

http://mapguy.ca