Query Engine Replica Load Balancer Node Installation
Audience: System Administrators
Content Summary: A load balancer should be installed and configured to act as a reverse proxy for the Query Engine Replica nodes. The load balancer should be installed on a dedicated node, but can be collocated with one of the Web Service nodes. If collocating, the web server node hosting the load balancer will be referred to for the remainder of this section as the query engine load balancer node.
Package Installation
Install haproxy on the query engine load balancer node.
Note: the following command must be run as
root
.
yum install haproxy
Configuration
Configure haproxy by creating /etc/haproxy/haproxy.cfg
:
global
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
defaults
mode http
log global
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 60m
timeout server 60m
timeout check 10s
maxconn 3000
listen query_engine_replicas *:5432
mode tcp
balance roundrobin
option tcp-check
# Create an entry for each replica node:
# Example: server <name> <query engine replica hostname>:5432 check port 5432
Finally, enable and start the haproxy service.
Note: the following commands must be run as
root
.
chkconfig haproxy on
service haproxy start