Rack and Varnish

Rack and Varnish

[froom]

Hi there

So URL1 request is passing through Rack.

Rack decides it needs to render URL2 instead (but not redirect the
browser, just render in place)

Is Rack able to pass the request to Varnish?

Or can Rack only pass on to other application layers, like Rails?

I'd like to pass back directly to Varnish if I can :)    Going
directly to Rails would break my cache.

thanks!

Re: Rack and Varnish

[Lee Hambley]

[-- Attachment #1: Type: text/plain, Size: 206 bytes --]

Sounds like you need to have your middleware return the user to the
front-end (Varnish Server) with an appropriate redirect header, be aware of
how Varnish handles redirect codes from it's backends.

- Lee

[-- Attachment #2: Type: text/html, Size: 239 bytes --]

Re: Rack and Varnish

[froom]

Thanks for the reply

Would rather not return a redirect response to the user/browser...
only want one request cycle

I'd rather Rack decided "I need to return the varnish cached page for
URL2 back to the user immediately".... and I was thinking the best way
to do that is modify the request in some way with a new URL, so almost
like a "restart" for the request, which would give Varnish a chance to
kick in before we bother Rails


Not sure if this is even feasible.... but seems preferable over
memcache storing entire pages for no real reason

Re: Rack and Varnish

[Lee Hambley]

[-- Attachment #1: Type: text/plain, Size: 363 bytes --]

>
> like a "restart" for the request, which would give Varnish a chance to
> kick in before we bother Rails


Sure, so redirect the user… or have your middleware get the page from Rack
for them, and return it (and beware of the significant performance hit, of
having your Ruby stack process cached pages… but at least it wouldn't hit
your Rails app)

[-- Attachment #2: Type: text/html, Size: 542 bytes --]