Hi, To summary, with httpclose, you have around 100 rps. With no option, you get 2K rps (which means your servers can do http keepalives). when you enable option http-server-close only, you have also 2K rps, because HAProxy does HTTP keepalive on the server side.
2 options: 1. there is a magic setup in JMETER which allows a maximum of 100 connections opened per bench (have a look at the concurrent pool size and tell us if its value, if any). 2. since you're in a virtual environment, when you disable keepalives on the client side, you're doing a lot of network exchange with very small packets, which is the worst case for any hypervisors. Have a look at the latest graph on this page, which shows the performance loss of each virtual network layer available on the market currently: http://blog.exceliance.fr/2012/04/24/hypervisors-virtual-network-performance-comparison-from-a-virtualized-load-balancer-point-of-view/ Cheers
