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
Using Discoverer Viewer with Oracle Web Cache to improve Web site performance, scalability, and availability would be most appropriate in the following cases:
■
Where Web sites only use public workbooks
■
Where Web sites access data that is relatively static
■
Where the Discoverer manager or workbook creator has access to Oracle Web Cache and can refresh the cache after changes to workbooks
After installing Oracle BI Discoverer, you must manually specify caching rules, as described in
Section 7.5.1, How to create Discoverer caching rules .
For security reasons, Oracle Web Cache only caches Discoverer Viewer pages that are accessed over a public connection.
Oracle Web Cache is particularly suitable for optimizing Discoverer Viewer performance when controlling access to data is relatively unimportant for example,
where the same public connections are used by several users to access workbooks. Oracle Web Cache is less suitable in restricted environments where controlling access
to data is an issue for example, where private connections are used by individuals to access their own workbooks. If you are considering using Oracle Web Cache in a
7-4 Oracle Fusion Middleware Configuration Guide for Oracle Business Intelligence Discoverer
restricted environment, note that a malicious user might be able to access pages that have been cached for another user. For more information about Oracle BI Discoverer
security in general, see Chapter 13, Maintaining Security with Oracle BI Discoverer.
7.5 How to use Discoverer Viewer with Oracle Web Cache
To use Discoverer Viewer with Oracle Web Cache, do the following:
■
Disable single sign-on. For more information, see Section 13.8.1.2, How to enable
and disable Single Sign-On for Discoverer.
■
Create caching rules for Discoverer on each Oracle BI middle-tier installation. For more information, see
Section 7.5.1, How to create Discoverer caching rules.
■
Enable Oracle Web Cache for Discoverer Viewer on each Oracle BI middle-tier installation. For more information, see
Section 7.5.2, How to enable Oracle Web Cache for Discoverer Viewer.
■
optional Configure Discoverer Viewer to ensure maximum caching. For more information, see
Section 7.5.3, How to configure Discoverer Viewer to enable maximum caching.
7.5.1 How to create Discoverer caching rules
Although Oracle Web Cache is installed with Oracle Fusion Middleware, it is disabled by default. To make use of Oracle Web Cache, you must create caching rules. For
example, you might want to cache Discoverer Viewer pages, or use a Discoverer middle-tier machine to provide load balancing.
To enable Oracle Web Cache for Discoverer Viewer:
1. Display the Discoverer Home page in Fusion Middleware Control. For more
information, see Section 4.1.2, How to start Fusion Middleware Control and
display the Farm Home page.
2. Navigate to the Web Cache node for example, wc1 in the navigation pane to
display the Web Cache Home page.
3. From the Web Cache menu, select Administration, and then select Caching Rules.
4. In the Caching Rules page that is displayed, click Create, to display the Create
Caching Rule page.
5.
Create a rule for caching URLs containing discovererapp.
a. In the Name field, enter a unique name for example, Discoverer caching
rule.
b. From the Match URL By drop-down list, select Path Prefix, and enter
discovererapp in the adjacent text box. Do not change the default values of the other fields.
c. Click OK to save the rule.
A confirmation message is displayed at the top of the page.
6.
Create a rule for URLs containing discovererviewer.
a. In the Name field, enter a unique name for example, Discoverer viewer
