What’s New in OracleAS Web Cache?

This section describes the new features of OracleAS Web Cache 10g (9.0.4) and provides pointers to additional information. New features information from previous releases is also retained to help those users migrating to the current release.

The following sections describe the new features:

• New Features in 10g (9.0.4)

• New Features in Release 2 (9.0.2 and 9.0.3)

New Features in 10g (9.0.4)

The new features for OracleAS Web Cache in 10g (9.0.4) include:

• New Invalidation Mechanisms

  • Support for Search Keys

    You can base invalidation on search keys used in the Surrogate-Key response-header field of objects in the cache.

    In previous releases, the URL-based cache key was the only identifier for a cached document. Invalidation requests needed to specify either exact URLs or a set of URLs and headers matching a regular expression in order to invalidate cached objects. Because it can be difficult for applications to map URLs to the underlying data used to generate those URLs, OracleAS Web Cache invalidation has been extended in 9.0.4 to support search keys. Cached objects can now be associated with multiple application-specified search keys, with the URL-based key being the primary key.

  • Support for Inline Invalidation with the <esi:invalidate> Tag

    This release introduces an inline invalidation mechanism as an additional means of managing content freshness. This inline invalidation model supplements the out-of-band invalidation model pioneered by Oracle in the very first release of OracleAS Web Cache. Inline invalidation is implemented as part of Edge Side Includes (ESI). The ability to send invalidation message inline reduces the connection overhead associated with sending out-of-band invalidations and is a useful tool for ESI developers.

    
    

    See Also: Chapter 11, " Sending Invalidation Requests "

    
    

• Usability and Manageability

  • Improved Access Logging, Event Logging, and Diagnostics

    Rollover policies for access and event logs are more flexible than in previous releases, and on-demand rollover has been added. Access log formats are now easier and more flexible to define. Administrators can also configure different access logs and logging formats for different virtual hosts serviced by the cache. New access log fields have been introduced that provide low-level request-timing diagnostics. With 9.0.4, OracleAS Web Cache provides event log support for four levels of verbosity instead of two, and many of the error messages have been improved (especially for ESI errors), both of which accelerate problem diagnosis and resolution. Finally, remote diagnostic tools have been enhanced to provide more information about response failures.

    
    

    See Also: Chapter 12, " Logging Events, Diagnostics, and Access Information"

    
    

  • Reporting on Popular Cache Misses

    Administrators can now use the browser-based OracleAS Web Cache Manager utility to get information about the most popular cache miss requests. This supplements reporting functionality in prior releases on the most popular objects in cache.

    
    

    See Also: "Listing Popular Requests and Cache Contents"

    
    

  • Integration with Oracle Process Manager and Notification (OPMN) Server

    In addition to managing Oracle HTTP Server and OC4J processes, OPMN now manages the admin server process and cache server process for OracleAS Web Cache, including the start, stop and auto-restart operations. For standalone OracleAS Web Cache deployments, administrators continue to use the webcachectl utility.

    
    

    See Also: "OPMN for Process Administration"

    
    

• Caching

  • More Flexible Multiple-Version Caching Rules for Browser Types

    In 9.0.4, you can better control the granularity of multiple-version caching rules based on User-Agent request headers (browser types). You can now configure a single cache entry for each browser type (Internet Explorer, Netscape, or Mozilla), as opposed to multiple entries for each browser variant (browser version, or operating system).

    
    

    See Also: "Recognizing Similar Browser Types for Multiple-Version Documents Containing HTTP Request Headers"

    
    

  • Expanded Expression Type Support

    In addition to using regular expressions, you can now apply caching rules to objects based on file extension or path prefix.

    
    

    See Also: "Selectors"

    
    

  • Maximum Size of Cached Documents

    To conserve resources, you can now configure the maximum size of documents to be cached.

    
    

    See Also: "Cached Object Size Limit"

    
    

• Security

  • Support for Client-Side SSL Certificates

    OracleAS Web Cache now supports applications that require client-side SSL certificates for PKI-based authentication. For HTTPS protocol requests that require client-side certificates, the client browser sends its certificate to Web Cache during the SSL handshake. The cache forwards the request to Oracle HTTP Server along with the client’s certificate information inserted in special HTTP request headers. Oracle HTTP Server recognizes the headers and is able to pass user credentials to Oracle Application Server Single Sign-On for authentication purposes.

    
    

    See Also: "Certificate"

    
    

  • Support for nCipher SSL Acceleration Hardware

    In addition to offboard SSL acceleration solutions, Oracle Application Server now supports nCipher’s BHAPI-compliant hardware for deployment on servers running OracleAS Web Cache and Oracle HTTP Server.

    
    

    See Also: "SSL Acceleration"

    
    

• Session Binding Across a Cluster

  OracleAS Web Cache provides a mechanism to ensure that all cache cluster members can determine which origin server established the session, although the request was routed originally through only one cache cluster member. As a result, subsequent requests are bound to the origin server that established the session.

  
  

  See Also: "Session Binding(Stateful Load Balancing)"

  
  

• End-User Performance Monitoring

  Using OracleAS Web Cache Manager, you can monitor the response time of your applications by viewing information about how quickly the responses are delivered to the end users.

  
  

  See Also: "Configuring End-User Performance Monitoring"

  
  

• Compression Enhancements

  • Self-Describing Compression Policies

    The Surrogate-Control response header now supports a compress control directive for enabling compression. This feature adds flexibility by enabling developers to express compression policies in the content itself, as opposed to relying on administrators to configure compression policies using the OracleAS Web Cache Manager.

  • More Compressible Content

    OracleAS Web Cache now compresses documents containing session-encoded URLs, ESI tags, or <!--WEBCACHETAG--> and <!-- WEBCACHEEND--> tags.

    
    

    See Also: "Surrogate-Control Response-Header Field"

    
    

• Improved ESI Exception Handling

  This release of ESI provides the following enhancements:

  • alt attribute of the <esi:include> tag for specifying an alternate URL if the src fragment is not found

  • Expanded try |attempt |except support for specific errors

    
    

    See Also: Chapter 15, " Edge Side Includes (ESI) Language Tags "

    
    

• Configuration Improvements

  • Configuration Improvements to OracleAS Web Cache Manager

    To help ease configuration, OracleAS Web Cache Manager supports a new navigation structure that resembles the order in which you perform configuration tasks. In addition, pages have been enhanced with purpose descriptions.

  • Dynamic Configuration

    A number of the configuration parameters in the browser-based OracleAS Web Cache Manager administration utility can now be changed on the fly, without requiring a restart of the cache.

    
    

    See Also: "Applying Static and Dynamic Configuration Changes"

    
    

  • Site Discovery

    OracleAS Web Cache Manager now provides support for discovering site and alias information from Oracle HTTP Server.

    
    

    See Also: "Create Site Definitions"

    
    

  • Default Sites

    During installation, OracleAS Web Cache defines a default site, using the host name and listening port of the computer on which the Oracle Application Server was installed.

    
    

    See Also: Default Site Settings

    
    

New Features in Release 2 (9.0.2 and 9.0.3)

The new features for OracleAS Web Cache in release 2 (9.0.3 and 9.0.2) include:

• Automatically Restarting a Cache Server

  The auto-restart checks that the cache server process is running and automatically restarts it if it is not running.

  
  

  See Also: "Task 3: Configure Auto-Restart Settings "

  
  

• Cache Hierarchy

  You can deploy OracleAS Web Cache in a cache hierarchy so that an OracleAS Web Cache server caches content from another OracleAS Web Cache.

  
  

  See Also: "Cache Hierarchies"

  
  

• Cache Clustering

  You can configure multiple instances of OracleAS Web Cache to run as members of a cache cluster. Cache clusters provide failure detection and failover of Web caches, increasing the availability of your Web site.

  
  

  See Also: Chapter 3, " Cache Clustering "

  
  

• ESI Enhancements

  This release of ESI provides support for the following:

  • Embedded HTML content with the <esi:inline> tag

  • Custom environment variables with the <esi:environment> tag

  • Expanded <esi:include> tag support that provides attributes for specifying expiration, fragment time out, and the HTTP request method. In addition, new elements enable you to specify the HTTP request body of a fragment and the HTTP request header field and value for OracleAS Web Cache to use.

    
    

    See Also: Chapter 15, " Edge Side Includes (ESI) Language Tags "

    
    

• HTTPS Support Between OracleAS Web Cache and Application Web Servers

  In addition to HTTPS protocol support between browsers and OracleAS Web Cache, you can configure OracleAS Web Cache for HTTPS support between OracleAS Web Cache and origin servers.

  
  

  See Also: "Secure Sockets Layer (SSL) "

  
  

• Invalidation Propagation

  Invalidation messages are propagated in a cache hierarchy whereby one OracleAS Web Cache server acts as an origin server for another OracleAS Web Cache server. They are also propagated in a cache cluster with multiple OracleAS Web Cache servers.

  
  

  See Also: "Invalidation in Hierarchies" "Invalidation in Cache Clusters"

  
  

• Invalidation Preview

  You can preview the list of documents to be invalidated.

  
  

  See Also: "Invalidation Preview Request Syntax" "Using OracleAS Web Cache Manager to Send Invalidation Requests"

  
  

• Listing the Contents of a Cache

  You can generate a list of the URLs of the most popular documents stored in the cache and a list of the URLs of all of the objects currently in the cache.

  
  

  See Also: "Listing Popular Requests and Cache Contents"

  
  

• Oracle Enterprise Manager Support

  You can use Oracle Enterprise Manager for monitoring OracleAS Web Cache. Oracle Enterprise Manager provides a Web-based tool that enables you to view OracleAS Web Cache status and performance metrics.

  
  

  See Also: "Oracle Enterprise Manager for Metrics " Oracle Application Server 10g Administrator's Guide

  
  

• Proxy Server Support

  In addition to application Web servers for internal sites, you can configure OracleAS Web Cache to send cache misses to proxy servers for external sites protected by a firewall.

  
  

  See Also: "Task 9: Configure Origin Server, Load Balancing, and Failover Settings "

  
  

• Site Support

  You can configure OracleAS Web Cache to cache and assemble dynamic content for one or more Web sites.

  
  

  See Also: "Virtual Hosting"

  
  

• webcachectl Commands

  The webcachectl utility provides commands for finer-grain control of the auto-restart process, cache server process, and admin server process.

  
  

  Note: If you are running OracleAS Web Cache in an environment where you have installed OracleAS Web Cache as part of an Oracle Application Server installation, you must use Oracle Process Manager and Notification (OPMN) Server to administer the OracleAS Web Cache processes. If you invoke the webcachectl utility in this situation, OracleAS Web Cache returns an error. See "OPMN for Process Administration" for information about OPMN.

  
  
  
  

  See Also: "webcachectl Utility Overview"