Configuring Root Privilege for Privileged Ports and More than 1,024 File Descriptors Configuring Root Privilege for the Current User

5-22 Oracle Fusion Middleware Administrators Guide for Oracle Web Cache installation. For setroot and revert modes, the user ID must be the ID of the user that performed the installation. The user ID must match the user ID specified in the Process Identity page Properties Process Identity of Oracle Web Cache Manager. See the Section 5.9 for further information about when running the webcache_ setuser.sh script is necessary. 6 Caching and Compressing Content 6-1 6 Caching and Compressing Content This chapter introduces techniques to cache and compress content using Oracle Web Cache. It discusses cache population, consistency, and rules. The chapter describes the properties for configuring caching rules and expiration policies. This chapter includes the following topics: ■ Section 6.1, About Cache Population ■ Section 6.2, About Cache Consistency ■ Section 6.3, About Caching Decisions ■ Section 6.4, Introduction to Creating Caching Rules ■ Section 6.5, Introduction to Configuring Advanced Settings ■ Section 6.6, Basic Tasks for Configuring and Monitoring Caching Rules ■ Section 6.7, Configuring Expiration Policies ■ Section 6.8, Configuring and Monitoring Caching Rules ■ Section 6.9, Monitoring Summary Settings for Caching Rules ■ Section 6.10, Using the Surrogate-Control Response Header as an Alternative to Caching Rules

6.1 About Cache Population

You define caching rules to determine which objects to cache. When you establish a caching rule, objects matching the rule are not cached until there is a client request for them. When a client first requests an object, Oracle Web Cache sends the request to the origin server . This request is a cache miss . Because this URL has an associated caching rule, Oracle Web Cache caches the object for subsequent requests. When Oracle Web Cache receives a second request for the same object, Oracle Web Cache serves the object from its cache to the client. This request is a cache hit . When you stop Oracle Web Cache, the cache clears all objects. In addition, Oracle Web Cache clears and resets statistics. See Section 6.3 for a description of how Oracle Web Cache determines cache population through caching rules.

6.2 About Cache Consistency

Consistency is crucial for the reliability of Oracle Web Cache. The following features ensure consistency between the cache and origin servers: