What are the benefits of Oracle Web Cache? How does Oracle Web Cache work?

7-2 Oracle Fusion Middleware Configuration Guide for Oracle Business Intelligence Discoverer Figure 7–1 Oracle Web Cache overview For more information about Oracle Web Cache, see Oracle Fusion Middleware Administrators Guide for Oracle Web Cache. Notes ■ When deploying Discoverer, you typically add Oracle BI installations to an Oracle Farm, and use Oracle Web Cache as a proxy server. For more information, see Chapter 6, Managing Discoverer in a Multi-Machine or Multi-Instance Environment. 7.2 What are the benefits of Oracle Web Cache? Using Oracle Web Cache: ■ Improves performance Running on inexpensive hardware, Oracle Web Cache can increase the throughput of a Web site by several orders of magnitude. In addition, Oracle Web Cache significantly reduces response time to browser requests by storing documents in memory and by serving compressed versions of documents to browsers that support the GZIP encoding method. ■ Improves scalability In addition to unparalleled throughput, Oracle Web Cache can sustain thousands of concurrent browser connections. The result is that visitors to a site see fewer application Web server errors, even during periods of peak load. ■ Offers high availability Oracle Web Cache supports content-aware load balancing and fail over detection. These features ensure that documents not in the cache referred to as cache misses are directed to the most available, highest-performing Web server in the cluster. Further features guarantee performance and provide surge protection when application Web server load increases. ■ Offers cost savings Fewer application Web servers are required to meet the challenges posed by traffic spikes and denial of service attacks. As a result, Oracle Web Cache offers a simple and inexpensive means of reducing a Web sites cost for each request. ■ Reduces network traffic Most requests are resolved by Oracle Web Cache, reducing traffic to the application Web servers. The cache also reduces traffic to back-end databases located on computers other than the application Web server. For more information about the benefits of using Oracle Web Cache, see Oracle Fusion Middleware Administrators Guide for Oracle Web Cache. Using Discoverer Viewer with Oracle Web Cache 7-3 7.3 How does Oracle Web Cache work? Oracle Web Cache uses cacheability rules to determine which documents to cache. A cacheability rule indicates whether you want the documents specified within a particular URL to be cached or not cached. Cacheability rules are defined using regular expressions for more information about Oracles implementation of regular expressions, see Oracle Fusion Middleware Administrators Guide for Oracle Web Cache. The document specified within a URL included in a cacheability rule is not actually cached until a browser requests it. Figure 7–2 The URL and document request process Key to figure: a . The first time a browser requests a particular URL, Oracle Web Cache detects that the required document is not in the cache referred to as a cache miss. Oracle Web Cache therefore forwards the request to an application Web server, which sends the request to the database. b . The database returns the data to the application Web server, which forwards a document and its URL to Oracle Web Cache. If the URL is specified as one of the URLs to cache, Oracle Web Cache caches the document for subsequent requests. c . The next time a browser requests the URL, Oracle Web Cache detects that the document is in the cache referred to as a cache hit. d . Oracle Web Cache serves the document from the cache to the browser.

7.4 When to use Discoverer Viewer with Oracle Web Cache