Caching in ColdFusion 2025

Caching Layers

A comprehensive caching strategy should use multiple layers to maximize performance:

• Edge Cache (CDN): Static assets, images, CSS, JavaScript
• HTTP Cache: Browser and reverse proxy caching
• Application Cache: Query results, computed values, objects
• Distributed Cache: Sessions, shared state across cluster
• Database Cache: Query plan cache, result cache

ColdFusion Built-in Caching

Template Cache

ColdFusion automatically caches compiled templates in memory. You can configure this behavior in the Administrator:

• Enable "Trusted Cache" in production environments for maximum performance
• Disable trusted cache in development so you can see template changes immediately
• Remember to clear the template cache after each deployment to production

Query Caching

<cfquery name="products" datasource="mydb" cachedWithin="#createTimeSpan(0,1,0,0)#">
    SELECT * FROM products WHERE category = <cfqueryparam value="#category#">
</cfquery>

<!-- Cache for 1 hour using createTimeSpan(hours, minutes, seconds, milliseconds) -->

Object Caching

<cfset cachePut("user_#userId#", userObject, createTimeSpan(0,0,30,0))>
<cfset cachedUser = cacheGet("user_#userId#")>
<cfif isNull(cachedUser)>
    <!--- Cache miss, load from database --->
</cfif>

Distributed Caching with Redis

For clustered or containerized environments, you should use Redis as a distributed cache to share data and sessions across all application nodes:

// Install Redis package via cfpm
cfpm install redis --acceptEULA

// Configure Redis cache in Application.cfc
this.cache.configFile = "redis-cache-config.xml";
this.sessionManagement = true;
this.sessionStorage = "redis";

Using Redis for session storage provides several important benefits:

• User sessions persist even when application servers restart
• Sessions are automatically shared across all cluster nodes
• Redis provides faster access than traditional database session storage
• Built-in automatic expiration and memory management keeps your cache clean

Cache Invalidation Strategies

"There are only two hard things in Computer Science: cache invalidation and naming things." - Phil Karlton

• Time-based: Expire after fixed duration
• Event-based: Invalidate on data change
• Manual: Clear specific keys when needed
• LRU: Least Recently Used eviction

<!--- Clear specific cache entry --->
<cfset cacheRemove("user_#userId#")>

<!--- Clear all cache in region --->
<cfset cacheRemove(arrayNew(1), true, "userCache")>

<!--- Clear specific query cache --->
<cfquery name="products" datasource="mydb" cachedWithin="#createTimeSpan(0,0,0,0)#">
    <!--- This clears the cache for this query --->
</cfquery>

Container and Stateless Considerations

For cloud-native deployments, follow these guidelines to ensure your caching strategy works in ephemeral container environments:

• Use an external distributed cache like Redis or Memcached instead of in-memory caching
• Avoid storing cached data in local files since container filesystems are ephemeral
• Store all uploaded files in object storage services like Amazon S3 or Azure Blob Storage
• Use container orchestration tools to implement cache warming during startup

HTTP Caching Headers

You should set proper HTTP headers to enable effective browser and CDN caching:

<cfheader name="Cache-Control" value="public, max-age=3600">
<cfheader name="ETag" value="#hash(content)#">
<cfheader name="Last-Modified" value="#dateFormat(now(), 'ddd, dd mmm yyyy')# #timeFormat(now(), 'HH:mm:ss')# GMT">

<!--- For non-cacheable content --->
<cfheader name="Cache-Control" value="no-cache, no-store, must-revalidate">
<cfheader name="Pragma" value="no-cache">
<cfheader name="Expires" value="0">