Client Variables page

Client variables let you store user information and preferences between sessions. Using information from client variables, you can customize page content for individual users.

You enable client variable default settings in ColdFusion MX on the Client Variables page of the Administrator. ColdFusion MX lets you store client variables in the following ways:

In database tables

If your data source uses one of the JDBC drivers bundled with ColdFusion, ColdFusion can automatically create the necessary tables. If your data source uses the ODBC Socket or a third-party JDBC driver, you must manually create the necessary CDATA and CGLOBAL database tables. For more information, see Developing ColdFusion MX Applications.

As cookies in users' web browsers

In the operating system registry

Caution: Macromedia recommends that you do not store client variables in the registry because it can critically degrade performance of the server. If you do use the registry to store client variables, you must allocate sufficient memory and disk space.

You can override settings specified in the Client Variables page using the attributes of the cfapplication tag. For more information, see Developing ColdFusion MX Applications.

The following table compares these storage options:

Storage type	Advantages	Disadvantages
Data source	Can use existing data source Portable: not tied to the host system or operating system	Requires database transaction to read/write variables More complex to implement
Browser cookies	Simple implementation Good performance Can be set to expire automatically Client-side control	Users can configure browsers to disallow cookies Cookie data to is limited to 4 KB Netscape Navigator allows only 20 cookies from one host; ColdFusion MX uses three cookies to store read-only data, leaving only 17 cookies available
System registry	Simple implementation Good performance Registry can be exported easily to other systems Server-side control	Possible restriction of the registry's maximum size limit in Windows in the Control Panel Integrated with the host system: not practical for clustered servers Solaris, Linux, and HP-UX registries are text files. Their registries deliver slow performance and low scalability.

Storage type

Advantages

Disadvantages

Data source

Can use existing data source
Portable: not tied to the host system or operating system

Requires database transaction to read/write variables
More complex to implement

Browser cookies

Simple implementation
Good performance
Can be set to expire automatically
Client-side control

Users can configure browsers to disallow cookies
Cookie data to is limited to 4 KB
Netscape Navigator allows only 20 cookies from one host; ColdFusion MX uses three cookies to store read-only data, leaving only 17 cookies available

System registry

Simple implementation
Good performance
Registry can be exported easily to other systems
Server-side control

Possible restriction of the registry's maximum size limit in Windows in the Control Panel
Integrated with the host system: not practical for clustered servers
Solaris, Linux, and HP-UX registries are text files. Their registries deliver slow performance and low scalability.

Version 6.1

Comments are no longer accepted for ColdFusion MX 6.1. ColdFusion 8 is the current version.

Comments

The Scotsman said on May 18, 2004 at 8:37 AM :

Using a Database to store the variables in CFMX will result in a HUGE performance decrease compared to the same setup in CF5 - a cfapplication tag in a standard Application.cfm file can take 2000ms compared to 0-16ms when using the Registry : could it be JDBC?

Current page: http://livedocs.adobe.com/coldfusion/6.1/htmldocs/basicon6.htm


Contents > Configuring and Administering ColdFusion MX > Basic ColdFusion MX Administration > Server Settings section > Client Variables page