Load Balancing and Clustering Liferay

There are two ways of Clustering Liferay on Tomcat

1. Sticky Session

User request will always goes to same Liferay instance

2. Session Replication

User request can go to any tomcat in cluster and his session is copied on entire cluster

Lets get started for Sticky Session based clustering and load balancing.

Use-Case

Setting up two tomcat Liferay along with apache on same windows machine.

Pre-requirements

1. install Apche 2.x

2. download Liferay5.x and make an extra copy

Steps 1. open httpd.conf from apache_home/conf/ and add these lines at the end

<Proxy balancer://mycluster>

BalancerMember ajp://localhost:8009/ route=tomcatA smax=15 max=50 loadfactor=20

BalancerMember ajp://localhost:8010/ route=tomcatB smax=15 max=50 loadfactor=20

</Proxy>

<Location / >

ProxyPass balancer://mycluster/ stickysession=JSESSIONID

</Location>

<Location /balancer-manager>

SetHandler balancer-manager

Order Deny,Allow

Deny from all

Allow from localhost

</Location>

Step 2.

uncomment the following four lines on httpd.conf

LoadModule proxy_module modules/mod_proxy.so

LoadModule proxy_ajp_module modules/mod_proxy_ajp.so

LoadModule proxy_balancer_module modules/mod_proxy_balancer.so

LoadModule status_module modules/mod_status.so

Step 3.

open liferay/tomcat_home_1/conf/server.xml and add jvmRoute="tomcatA" to the following line

Engine name="Catalina" defaultHost="localhost"

so it should look like this

Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatA"

Step 4.

open liferay/tomcat_home_2/conf/server.xml and add jvmRoute="tomcatB" to the following line

Engine name="Catalina" defaultHost="localhost"

so it should look like this

Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcatB

also change the following port nos

Server port="8006" shutdown="SHUTDOWN"

Connector port="8081" protocol="HTTP/1.1"

connectionTimeout="20000"

redirectPort="8444"

Connector port="8010" protocol="AJP/1.3" redirectPort="8444"

Thats It!

start apache, tomcatA, tomcatB and

navigate to http://localhost/

also checkout balancer-manager

http://localhost/balancer-manager

for more configuration and understanding checkout the following link

http://httpd.apache.org/docs/2.2/mod/mod_proxy.html

If your tomcats run on different server make sure you change index directory to some central place (e.g /common-dir/liferay ) i.e resource.repositories.root=/common-dir/liferay in portal-ext.properties