Just wondering if it is possible to have nginx, apc, memcached, and varnish all running together. i am currently running on a dreamhost private virtual server, not that it matters. any input would be greatly appreciated.
Yes, it is. It will get a little crowded and maybe
is it that you are intending?
We currently do this in our environment. Specifically:
nginx -> varnish -> apache (with memcached & apc installed). We do this on a RHEL5 box (64bit).
We added the nginx layer mainly to provide gzip compression on the outgoing requests. It works really well.
One tricky part is keeping the real IP of the initial client all the way down to the apache layer. We achieved this by implementing some custom headers in Varnish's VCL