Load Balancing with Apache

Load Balancing with Apache from Bradley Holt

I’ve posted the example configuration files for reference.

	# Create a load balancer named "web-nodes"
	<Proxy balancer://web-nodes>
	# Add three load balancer members
	BalancerMember http://www1.example.com
	BalancerMember http://www2.example.com
	BalancerMember http://www3.example.com
	</Proxy>
	# Send all requests to the "web-nodes" balancer
	ProxyPass / balancer://web-nodes

	# Create a load balancer named "web-nodes"
	<Proxy balancer://web-nodes>
	# Add three load balancer members
	BalancerMember http://www1.example.com
	BalancerMember http://www2.example.com
	BalancerMember http://www3.example.com
	# Use the PHPSESSID for sticky sessions
	ProxySet stickysession=PHPSESSID
	</Proxy>
	# Send all requests to the "web-nodes" balancer
	ProxyPass / balancer://web-nodes

	# Set a cookie
	Header add Set-Cookie "NODE=%{BALANCER_WORKER_ROUTE}e; path=/" \
	env=BALANCER_ROUTE_CHANGED
	# Create a load balancer named "web-nodes"
	<Proxy balancer://web-nodes>
	# Add three load balancer members
	BalancerMember http://www1.example.com route=1
	BalancerMember http://www2.example.com route=2
	BalancerMember http://www3.example.com route=3
	# Use the NODE cookie for sticky sessions
	ProxySet stickysession=NODE
	</Proxy>
	# Send all requests to the "web-nodes" balancer
	ProxyPass / balancer://web-nodes

	# Enable mod_rewrite
	RewriteEngine On

	# Send POST, PUT, and DELETEs to "write" balancer
	RewriteCond %{REQUEST_METHOD} ^(POST\|PUT\|DELETE)$
	RewriteRule ^/(.*)$ balancer://write$1 [P]

	# Send GET, HEAD, and OPTIONS to "read" balancer
	RewriteCond %{REQUEST_METHOD} ^(GET\|HEAD\|OPTIONS)$
	RewriteRule ^/(.*)$ balancer://read$1 [P]

	# Modify HTTP response headers (e.g. Location)
	ProxyPassReverse / balancer://write
	ProxyPassReverse / balancer://read

	<?xml version="1.0"?>
	<!DOCTYPE tsung SYSTEM "/usr/share/tsung/tsung-1.0.dtd">
	<tsung loglevel="notice" version="1.0">

	<!-- Client side setup -->
	<clients>
	<client host="test-a" weight="1" maxusers="10000" cpu="4" />
	<client host="test-b" weight="1" maxusers="10000" cpu="4" />
	</clients>

	<!-- Server side setup -->
	<servers>
	<server host="www" port="80" type="tcp" />
	</servers>

	<!-- Load setup -->
	<load>
	<arrivalphase phase="1" duration="5" unit="minute">
	<users arrivalrate="200" unit="second" />
	</arrivalphase>
	</load>

	<!-- Session setup -->
	<session name="default" probability="100" type="ts_http">
	<thinktime value="1" random="true" />
	<request>
	<http method="GET" url="/" />
	</request>
	</session>

	<!-- Monitoring setup -->
	<monitoring>
	<monitor host="www" type="munin" />
	<monitor host="www1" type="munin" />
	<monitor host="www2" type="munin" />
	<monitor host="www3" type="munin" />
	</monitoring>

	</tsung>

view raw tsung.xml hosted with ❤ by GitHub

I cover load balancing and distributed load testing in more detail in my upcoming book, Scaling CouchDB.

Bradley Holt