System information

CONFIGURING AND ADMINISTERING COLDFUSION 9

Using Multiple Server Instances

Last updated 2/21/2012

Configure multiple server instances for application isolation when using Sun ONE Web

Server

Run the Web Server Configuration Tool for each Sun ONE Web Server instance. Specify a different configuration

directory and ColdFusion server instance each time. Ensure that you select the Configure Web Server for ColdFusion

MX Applications option (GUI) or use the -

coldfusion option (command line).

Enabling clustering for load balancing and failover

Load balancing is an enterprise-level feature in which the application server automatically alternates requests among

the server instances in a cluster. Clustering also enables application servers to route requests to a running server

instance when the original server instance goes down.

Note: These instructions apply only when you are running ColdFusion in the multiserver configuration. If you are

running JRun4, you can also create clusters in the JMC.

You can get load balancing and failover by deploying identical ColdFusion applications and configurations to multiple

server instances and adding the instances to a cluster. Each instance must have the same applications deployed and the

same resources configured (such as data sources, Verity collections, and mappings). The web server connector

optimizes performance and stability by automatically balancing load and by switching requests to another server

instance when a server instance stops running.

Note: Because clustering uses Jini Network Technology, you must be connected to a network for clustering to work.

For maximum failover protection, use multiple computers in a cluster. However, purchase a separate ColdFusion

Enterprise Edition license for each computer.

Note: If you set up and test multiple server instances while running the 30-day trial version, the cluster might not continue

to function appropriately when the trial version reverts to the Developer version after 30 days.

To implement session failover for the server instances in a cluster, enable session replication for each server instance.

Session replication coordinates session information in real time among the server instances in a cluster. Enabling

session replication lets JRun automatically route a request to a running server if the current server is unavailable.

Note: When a cluster uses session replication, session data is copied to other servers in the cluster each time it is modified.

This can degrade performance if you store a significant amount of information in session scope. If you plan to store a

significant amount of information in session scope, consider storing this information in client variables saved in a

database.

To enable session replication, manually edit the jrun-web.xml and set persistence to false. To do this, open the

jrun_root/servers/server_name/server_name-ear/server_name-war/WEBINF/jrun-web.xml file and modify the

<persistence-config> entry to false as follows:

<persistence-config><active>false</active></persistence-config>

For more information, see TechNote "JRun 4: Configuring session replication to enable session failover" at

www.adobe.com/go/tn_18226.

Configure a cluster of server instances for load balancing and failover

1 Create your application and the data sources required for the application.

2 Check that you installed ColdFusion by using the multiserver configuration.

3 Open the ColdFusion Administrator for the cfusion server in a browser

(http://hostname:8300/CFIDE/administrator).