I recently installed HAProxy as a web server load balancer. While their documentation is great, I found it lacking a complete example of a working configuration file. For reference, here is the config file I ended up with along with comments.

# /etc/haproxy/haproxy.cfg, version 1.4

global
   maxconn 4096
   user haproxy
   group haproxy
   daemon

defaults
   log   global
   mode   http
   # logs which servers requests go to, plus current connections and a whole lot of other stuff 
   option   httplog
   option   dontlognull
   retries   3
   option redispatch
   maxconn   2000
   contimeout   5000
   clitimeout   50000
   srvtimeout   50000
   log        127.0.0.1       local0
   # use rsyslog rules to forword to a centralized server  
   log        127.0.0.1       local7 debug
   # check webservers for health, taking them out of the queue as necessary 
   option httpchk

# this load balancer servers both www.site.com and static.site.com, but those two URLS have  
# different servers on the backend (app servers versus statis media apache instances)  
# also, I want to server www.site.com/static/* from the later farm  

frontend http

   bind 0.0.0.0:80

   # important, see comment from Willy Tarreau bellow
   option http-server-close

   # NAT static host names and static paths in other hostnames to static.bullhornreach.com
   acl host_static hdr_beg(host) -i static
   acl url_static  path_beg    /static
   use_backend static if host_static
   use_backend static if url_static

    default_backend www

backend www
   balance roundrobin
   server www1 www1 check port 80
   server www2 www2 check port 80
   server www3 www3 check port 80
   # provide a maintenance page functionality, only used when all other servers are down
   server load1 localhost:8080 backup

backend static
   # for static media, connections are cheap, plus the client is very likely to request multiple files  
   # so, keep the connection open (KeepAlive is the default)  
   balance roundrobin
   server media1 media1 check port 80
   server media2 media2 check port 80

listen stats :1936
   mode http
   stats enable
   stats scope http
   stats scope www
   stats scope static
   stats scope static_httpclose
   stats realm Haproxy\ Statistics
   stats uri /
   stats auth haproxy:YOURPASSWORDHERE

Edit: made changes suggested by Willy Tarreau.