Pablo Alsina's questions

We currently have a DRBD based replication on an pair of Asterisk servers, where we use DRBD for file and MySQL data replication on an active/passive usage scenario, using protocol B (semi-synchronous). Heartbeat handles the failover.

We are currently syncing over a back-to-back Gbit Ethernet, that will now be replaced with some switches and a fiber interconnect, as we would like to have active and passive server on different (physical) locations.

What are the network requirments of the interconnect in order to archive a proper DRBD setup? I would like to find out what the requirements are in terms of latency, packet loss, jitter, etc. (ignoring bandwidth, as that would be a function of the amount of data needed to be synced).

I've seen Linbit offers "DRBD Proxy" for WAN scenarios, but thats not the case here, it's still a LAN enviroment with (relative) low latency and packet loss. Or stated differently: when does it become neccesary to use DRBD Proxy, how "bad" should the network be?

This similar question touches the issue, but does not state specific requierements or real-world limits.

I provide hosting facilities for a high traffic website that will receive a spike in traffic in the next 2 months. In order to allow more it to perform better, I want to prepare myself and put a frontend server acting as a reverse proxy and direct traffic through it.

What reverse proxy do you suggest I use?

I've used Apache mod_proxy in the past with some good results, but is there something more performant out there, something more specific for the job? I need it to be fast, to do caching of all it can, and avoid doing requests when not needed.

I thought about HAProxy, but it seems to be more directed to provide High availability (multiple backend webservers). On this setup, the whole website is hosted on a single server, running some LAMP stuff.