Hi Dário,
> It's for my thesis work but see it like this: > I have 2 servers: test and production. I want forward the same request > to both, collect/log the responses and compare them (similar to parallel > proxy) I see. Well haproxy cannot this and I doubt you will find a proxy capable to do this, as this a very specific/exotic requirement. You will probably need to write some code on your own, perhaps in a scripting language (python could probably do the job just find with the right libs). Regards, Lukas