Re: Establishing connection lasts long

On Tue, Sep 13, 2011 at 03:31:21PM +0200, Tim Korves wrote:
> Hi there,
>
> >This has nothing to see with haproxy but more how your hypervisor
> >manages VMs which doesn't do anything :)
>
> thanks for the information. Do you have any tips regarding vmWare ESXi
> 4.1 ?

First, the common suspect : are all of your VMs on the same HV ? Quite commonly, what is observed is that involving multiple VMs adds huge delays, especially if more total logical CPUs are allocated than the total physical ones (which is to be expected because the HV has to schedule everyone in turn).

The other common issue when you see something slowing down through haproxy is a lack of tuning of the OS, specifically conntrack, but this is not related to the VMs at all, it's general. Just in case, unload the nf_conntrack module from the machine running haproxy. If it changes anything, then either you have to definitely remove it because you don't use it, or you need to tune your whole system, which is often quite an amusing exercise in VMs ;-)

Regards,
Willy Received on 2011/09/14 00:34