MACROMEDIA COLFUSION MX 7 - INSTALLING AND USING COLDFUSION..., Manual

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94 Chapter 7: Using Multiple Server Instances
Enabling application isolation
You can create separate server instances, each with its own ColdFusion applications; each
application then has its own ColdFusion and J2EE server resources. In this configuration, you
typically have a single external web server with multiple server instances on one computer, and
separate virtual hosts (or sites) for each server instance.
Note: Although this section describes using ColdFusion MX, other J2EE application servers provide
equivalent capabilities, and most of the concepts apply when deploying the ColdFusion MX J2EE
configuration on those J2EE servers.
Running independent applications this way has several advantages, including the following:
•
Errors at the levels of the ColdFusion application or the JRun server do not affect any other
ColdFusion applications.
•
You can support multihomed servers, where a single web server supports multiple IP addresses
or domain names, such as www.mycompany.com and services.anothercompany.com, each
running from a separate web root. For more information, see
“Multihoming” on page 74 .
•
Individual applications can use different JVM configurations, or even different JVM
implementations. This feature is particularly useful if one application requires a particularly
large Java heap. To specify customized JVM options, start the JRun server instance from the
command line using the
-config
option of the
jrun
command, which specifies a customized
jvm.config file. This is explained in the “Starting and stopping JRun servers” section in
Installing and Using ColdFusion MX .
Note: These instructions describe creating multiple server instances on a single computer. To create
multiple server instances on separate computers, each computer requires a separate license of
ColdFusion MX Enterprise Edition.
To achieve complete application isolation, you use web-server-specific functionality to create a
separate website for each application. Web servers have different terminology for this concept. For
example, in IIS, you define separate websites (available in Windows server editions only) and in
Apache, you create multiple virtual hosts.
These instructions apply when running ColdFusion MX in the multiserver configuration. The
principles apply when running ColdFusion MX on other J2EE application servers. However, not
all J2EE application servers integrate with external web servers. For more information, see
“Multihoming” on page 74 .
These instructions assume that you deploy each application at a named context root, which
enables users to access CFM pages by specifying http://
hostname / context-root / pagename .cfm. If
other web applications are running in the server instance, each web application must use a
different context root.
For example, with a context root of cfmx, users access CFM pages by specifying
http://
hostname / cfmx / pagename .cfm. For more information on using a context root, see Installing
and Using ColdFusion MX .
Note: Although cfmx is the context root, it does not relate to your web application directory structure.