Using Server Variables - MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX Develop Manual

Because each Application scope variable is shared in memory by all requests in the application,
these variables can become bottlenecks if used inappropriately. Whenever a request is reading or
writing an Application scope variable, any other requests that use the variable must wait until the
code accessing the variable completes. This problem is increased by the processing time required
for locking. If many users access the application simultaneously and you use Application scope
variables extensively, your application performance might degrade. If your application uses many
application variables, consider whether the variables must be in the Application scope or whether
they can be Session or Request scope variables.
The application scope has one built-in variable,
contains the application name you specify in the
You access and manipulate application variables the same way you use session variables, except
that you use the variable prefix Application, not Session, and specify Session as the lock scope. For
examples of using session variables see
"Accessing and changing session variables" on page
For information on locking write-once read-many application variables efficiently, see
application variables efficiently" on page 339

Using server variables

Server variables are associated with a single ColdFusion server. They are available to all
applications that run on the server. Use server variables for data that must be accessed across
clients and applications, such as global server hit counts.
Server variables do not time out, but they are lost when the server shuts down. You can delete
server variables.
Server variables are stored on a single server. As a result, you should not use server variables if you
use ColdFusion on a server cluster.
You access and manipulate server variables the same way use Session and application variables,
except you use the variable prefix Server.
Caution: To preserve data integrity, put code that uses server variables inside
not have to lock access to built-in server variables.
ColdFusion provides the following standard built-in read-only server variables:
Variable
Server.ColdFusion.AppServer
Server.ColdFusion.Expiration
Server.ColdFusion.ProductLevel
Server.ColdFusion.ProductName
Server.ColdFusion.ProductVersion
Server.ColdFusion.Rootdir
332 Chapter 15: Using Persistent Data and Locking
Application.applicationName
cfapplication
"Creating and deleting session variables" on page 329
330.
Description
The name of the J2EE application server ColdFusion is
using. For ColdFusion MX server editions, which have an
integrated application server, the name is JRun4.
The date, in ODBC date format, on which the ColdFusion
MX license expires. (A null string in all but trial versions of
ColdFusion.)
The server product level, such as Enterprise.
The name of the product (ColdFusion MX).
The version number for the server that is running, such as
6,0,0.
Directory under which ColdFusion is installed, such as
C:\cfusion.
, which
tag.
"Locking
tags. You do
cflock
and