User Guide

Table Of Contents
Optimizing ColdFusion applications 299
The ColdFusion MX Administrator provides caching options for ColdFusion pages and SQL
queries. For information on these options, see the ColdFusion MX Administrator online Help
and Configuring and Administering ColdFusion MX.
For information on debugging techniques that can help you identify slow pages, see Chapter 18,
“Debugging and Troubleshooting Applications,” on page 423.
For additional information on optimizing ColdFusion, see the Macromedia ColdFusion support
center at www.macromedia.com/support/coldfusion.
Caching ColdFusion pages that change infrequently
Some ColdFusion pages produce output that changes infrequently. For example, you might have
an application that extracts a vendor list from a database or produces a quarterly results summary.
Normally, when ColdFusion gets a request for a page in the application, it does all the business
logic and display processing that are required to produce the report or generate and display the
list. If the results change infrequently, this can be an inefficient use of processor resources and
bandwidth.
The
cfcache tag tells ColdFusion to cache the HTML that results from processing a page request
in a temporary file on the server. This HTML does not need to be generated each time the page is
requested. When ColdFusion gets a request for a cached ColdFusion page, it retrieves the
pregenerated HTML page without having to process the ColdFusion page. ColdFusion can also
cache the page on the client. If the client browser has its own cached copy of the page from a
previous viewing, ColdFusion instructs the browser to use the client’s page rather than resending
the page.
Note: The cfcache tag caching mechanism considers that each URL is a separate page. Therefore,
http://www.mySite.com/view.cfm?id=1 and http://www.mySite.com/view.cfm?id=2 result in two
separate cached pages. Because ColdFusion caches a separate page for each unique set of URL
parameters, the caching mechanism accommodates pages for which different parameters result in
different output.
Using the cfcache tag
You tell ColdFusion to cache the page results by putting a
cfcache tag on your ColdFusion page
before code that outputs text. The tag lets you specify the following information:
Whether to cache the page results on the server, the client system, or both. The default is both.
The default is optimal for pages that are identical for all users. If the pages contain client-
specific information, or are secured with ColdFusion user security, set the
action attribute in
the
cfcache tag to ClientCache.
The directory on the server in which to store the cached pages. The default directory is cf_root/
cache. It is a good practice to create a separate cache directory for each application. Doing so
can prevent the
cfcache tag flush action from inappropriately flushing more than one
applications caches at a time.
The time span that indicates how long the page lasts in the cache from when it is stored until it
is automatically flushed.