[CentOS] Load balancing...

Fri Mar 4 19:18:33 UTC 2011
James Nguyen <james at callfire.com>

On Fri, Mar 4, 2011 at 9:34 AM, Todd <slackmoehrle.lists at gmail.com> wrote:
> Brian,
> Thanks for all of the great words here. I appreciate the detail in your
> reply.
>> OK, so what's good?  For my requirements, HAProxy is excellent.  It
>> handled sticky sessions well, performs monitoring of each host, allows
>> dynamic adding/removing of servers, as well as maintenance modes.
>> It's very easy to install and configure.  I'm using is as the backend
>> to apache that is acting as an SSL termination point.  It's been very
>> high performing for us and I know a lot of big sites use it as well.
>> The only question I would have with it is handling of video, as we
>> only use it for typical web traffic, just high bandwidth stuff like
>> that.
>> Also, make sure any load balancer you have is redundant and has some
>> kind of failover, using something like pacemaker, heartbeat, etc...
> Can you outline a bit specs for building a homemade box to run HAProxy? The
> HAProxy site is very extensive, but I did not see ideal specs at a quick
> glance. I will read in depth this weekend.
> Minimal specs and they excellent specs if you have thoughts.. I really don't
> have an idea how intensive a task like this is. Nobody needs to log into the
> box, simply use the box for this purpose.
> -Jason
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You want two boxes that run both haproxy + keepalived.  This way you
get the load balancing (HAProxy) plus the high availability
(Keepalived) using a shared virtual IP for your two boxes.  You can do
maintenance on either one while traffic still remains active.

I don't have metrics to spec out the boxes, but given your traffic
load you mentioned you don't need hefty boxes at all.  Just get
yourself a box with some Gigabit interfaces which I'm sure they all
are these days.  A single socket with 4 cores is more than enough.
You can probably even do with 2 cores.  Someone can correct me on that
if they think the solution requires a lot of CPU.  Memory wise I think
machines come with at least 4Gb these days.  That should do.  You can
probably both boxes for around 2k?

You already know how much F5 or any of those guys cost per device. =)

James H. Nguyen
CallFire :: Systems Architect