Enabling Load Balancing And Failover - MACROMEDIA COLDFUSION MX 61 - CONFIGURING AND ADMINISTERING COLDFUSION MX Manual

Configuring application isolation in SunONE Web Server
When using multiple virtual hosts with multiple server instances under SunONE Web Server,
you create multiple SunONE Web Server instances, one for each ColdFusion server instance.
This discussion assumes that you have already created server instances, as described in
application isolation" on page
To configure multiple server instances for application isolation when using SunONE Web
Server:
•
Run the Web Server Configuration Tool multiple times, once for each SunONE Web Server
server instance, specifying a different configuration directory and ColdFusion server instance
each time.

Enabling 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 running ColdFusion MX on JRun. When deploying
ColdFusion MX on other J2EE application servers, consult the application server documentation for
information on enabling session replication.
You can get load balancing and failover by deploying the ColdFusion application to multiple
server instances and adding the instances to a cluster. 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.
For maximum failover protection, use multiple computers in a cluster. However, you must
purchase a separate ColdFusion MX license for each computer.
Note: If you set up and test multiple server instances while running the 30-day Trial version, the
cluster may not continue to function appropriately when the Trial version reverts to Developer version
after 30 days.
To implement failover for the server instances in a cluster, you must enable session replication.
Session replication coordinates session information in real-time among the server instances in a
cluster. Enabling session replication lets a request be automatically routed to a running server if
the current server is unavailable.
To configure a cluster of server instances for load balancing and failover:
Create server instances for the cluster as described in
1
on page 76.
Deploy ColdFusion on each server instance as described in
2
on page 76.
Start each server instance.
3
Open the ColdFusion MX Administrator on each server instance using the built-in web server.
4
Define the resources (such as data sources and Verity collections) required for the application.
If using failover, go to the Memory Variables pages, and enable J2EE sessions. You must do this
for all server instances in the cluster.
Note: Session variables are the only memory variables that support failover. In particular,
ColdFusion components do not support failover.
77.
"Defining additional server instances"
"Deploying ColdFusion MX"

Enabling load balancing and failover

"Enabling
81