Release 2 (9.0.2)
Part Number A95404-02
 Home |
 Solution Area |
 Contents |
 Index |
| Oracle9iAS Web Cache Administration and Deployment Guide Release 2 (9.0.2) Part Number A95404-02 |
|
A log file that contains information about the HTTP requests sent to Oracle9iAS Web Cache for a Web site. The access log has a file name of access_log and is stored by default in $ORACLE_HOME/webcache/logs and ORACLE_HOME\webcache\logs on Windows.
An Oracle9iAS Web Cache process that provides administration, configuration, and monitoring capabilities.
An origin server that manages data for a Web site, controls access to that data, and responds to requests from Web browsers. The application on the Web server interfaces with the database and performs the job requested by the Web server.
An Oracle9iAS Web Cache process that checks if the cache server process server process is running and automatically restarts the cache server process if it is not running
An HTTP Web browser request that can be satisfied from the Oracle9iAS Web Cache cache without going to the origin server.
A loosely coupled collection of cooperating Oracle9iAS Web Cache cache instances working together to provide a single logical cache. Cache clusters provide failure detection and failover of Web caches, increasing the availability of your Web site.
An instance of Oracle9iAS Web Cache configured with other instances of Oracle9iAS Web Cache to operate as one logical cache. The cache cluster members communicate with one another to request cacheable content that is cached by another cache cluster member and to detect when a cache cluster member fails.
A deployment in which an Oracle9iAS Web Cache caches content from another Oracle9iAS Web Cache to a local market. Oracle9iAS Web Cache provides support for a distributed cache hierarchy in a distributed network and an ESI cache hierarchy in an ESI provider site configuration.
An HTTP Web browser request that cannot be satisfied from the Oracle9iAS Web Cache cache and most go to an origin server.
An Oracle9iAS Web Cache process that manages the cache by providing connection management and request processing.
The maximum number of concurrent connections that the origin server can accept.
A cookie that enables the multiple version of the same page to served to different categories of users.
In adistributed cache hierarchy, an Oracle9iAS Web Cache server that acts as an origin server to at least one remote cache. When content becomes invalid, the central cache propagates the invalidation request to the remote caches to ensure consistency.
See Common LogFile Format (CLF).
An industry-standard format for Web transaction log files.
A packet of state information sent by an origin server to a Web browser during an HTTP request. During subsequent HTTP requests, the cookie is passed back to the origin server, enabling the origin server to remember the state of the last transaction. Some uses of cookies include:
A cache hierarchy in which a central cache acts as an origin server to a remote cache.
A system for naming computers and network services that is organized into a hierarchy of domains. DNS is used in TCP/IP networks to locate computers through user-friendly names. DNS resolves a friendly name into an IP address, which is understood by computers.
Markup declarations that provide a grammar for a class of documents.
A markup language to enable partial page caching of HTML fragments.
Parameter information embedded in the URL of documents. Oracle9iAS Web Cache accepts requests that use the following characters as delimiters: question mark (?), ampersand (&), dollar sign ($), or semi-colon (;).
A cache hierarchy in which a provider cache acts as an origin server to a subscriber cache.
A site that Oracle9iAS Web Cache contacts for Edge Side Includes (ESI) assembly only. Browsers are not allowed to request content from these sites.
A log file that contains Oracle9iAS Web Cache event and error information. The event log has a file name of error_log and is stored in $ORACLE_HOME/webcache/logs on UNIX and ORACLE_HOME\webcache\logs on Windows.
Time when documents are no longer valid in the cache and are refreshed.
A language that offers a flexible way to create common information formats. XML is used for invalidation messages and responses.
When an origin server fails, Oracle9iAS Web Cache automatically distributes the load over the remaining origin servers and polls the failed origin server for its current up/down status until it is back online. In a cache cluster environment, Oracle9iAS Web Cache transfers ownership of the content of the failing member to the remaining cluster members.
In a cache cluster environment, Oracle9iAS Web Cache detects when a cache cluster member is unavailable.
An HTTP request method used for simple requests for Web pages. A GET method is made up of a URL. Requests for pages that use the GET method are typically cached.
An HTTP request method made up of a URL and a query string containing parameters and values. An example of an HTTP GET with query string follows.
http://www.myserver.com/setup/config/navframe?frame=default
This request executes a script named navframe in the /setup/config directory of the www.myserver.com server and passes the script a value of default for the frame variable.
Hypertext Transport Protocol. A protocol that provides the language that enables browsers and the origin server to communicate.
A header that enables Web browsers to pass additional information about the request and about itself to the origin server.
A method included in the HTTP request that specifies the purpose of the client's request. HTTP supports many methods, but the ones that concern caching are GET, GET with query string, and POST methods.
Secure Hypertext Transfer Protocol. A protocol that uses the Secure Sockets Layer (SSL) to encrypt and decrypt user page requests as well as the pages that are returned by the origin server.
Oracle9iAS Web Cache function that marks documents as invalid and then refreshes them with updated content from the origin server. Invalidation keeps the Oracle9iAS Web Cache cache consistent with the content on the origin servers.
In a cache cluster environment, Oracle9iAS Web Cache propagates invalidation messages to other cache cluster members. It sends the invalidation messages to one cache cluster member who acts as the coordinator. The coordinator propagates the invalidation messages to the other cluster members.
Used to identify a node on a network. Each computer on the network is assigned a unique IP address, which is made up of the network ID, and a unique host ID. This address is typically represented in dotted-decimal notation, with the decimal value of each octet separated by a period, for example 144.45.9.22.
Networking round-trip time.
A feature in which HTTP requests are distributed among origin servers so that no single server is overloaded.
A networking switch that operates at Layer 4 of the Open Systems Interconnection (OSI) model--the Transport layer. L4 switches base their switching decisions on the TCP/IP protocol header and determine, based on the port number, where to pass traffic.
A networking switch that operates at Layer 7 of the OSI model--the Application layer. L7 switches base their switching decisions on URL content.
A network switch that balances the load of incoming browser request. In an Oracle9iAS Web Cache deployment, the Load Balancer is typically positioned in front of the Oracle9iAS Web Cache server.
In a cache cluster environment, on-demand content are popular documents that are stored in the cache of each cluster member.
A model of network architecture developed by ISO as a framework for international standards in heterogeneous computer network architecture.
The OSI architecture is split between seven layers, from lowest to highest:
1. Physical layer
2. Data link layer
3. Network layer
4. Transport layer
5. Session layer
6. Presentation layer
7. Application layer
Each layer uses the layer immediately following it and provides a service to the preceding layer.
See Open Systems Interconnection (OSI).
A tool for administering Oracle9i Application Server. It is a complete management solution for administering, configuring, and monitoring the application server and its components. Using it, you can:
A tool that combines configuration abilities with component control to provide an integrated environment for configuring and managing Oracle9iAS Web Cache.
A server that is either an application Web server for internal sites or a proxy server for external sites protected by a firewall.
In a cache cluster environment, content that is owned by a particular cache cluster member. Oracle9iAS Web Cache distributes the cached content among the cache cluster members. In effect, it assigns content to be owned by a particular cache cluster member.
A feature that enables Oracle9iAS Web Cache to independently cache and manage fragments of HTML documents. A template page is configured with Edge Side Includes (ESI) markup tags that tell Oracle9iAS Web Cache to fetch and include the HTML fragments. The fragments themselves are HTML files containing discrete text or other objects.
Heuristics that enable Oracle9iAS Web Cache to assign a queue order to documents. These heuristics determine which documents can be served stale and which documents must be retrieve immediately. While documents with a higher priority are retrieved first, documents with a lower priority are retrieved at a later time.
The queue order of documents is based on the popularity of documents and the validity of documents assigned during invalidation. If the current load and capacity of the origin server is not exceeded, then the most popular and least valid documents are refreshed first.
Pages that contain personalized attributes, such as personalized greetings like "Hello, Name," icons, addresses, or shopping cart snippets, on an otherwise generic page. You can configure Oracle9iAS Web Cache to substituting values for personalized attributes based on the information contained within a cookie or an embedded URL parameter.
The number of requests for a document since entering the cache and the number of recent requests for the document.
An HTTP request method used for requests that modify the contents of the data store on the origin server, such as posting a message to a mailing list, submitting forms for registration purposes, or adding entries to the database.
An origin server that substitutes for the real server, forwarding client connection requests to the real server or to other proxy servers. Proxy servers provide access control, data and system security, monitoring, and caching.
Set of content--content areas, pages, applications, even data from outside sources--brought together in one central location and accessed through a common interface, called a page.
In an ESI cache hierarchy, an Oracle9iAS Web Cache server that locally caches content for a provider site. A subscriber cache then contacts the provider caches for assembly of HTML fragments. When content becomes invalid, the provider cache propagates the invalidation request to the subscriber cache to ensure consistency.
A site that provides as a source of content for a provider cache and a subscriber cache.
Oracle9iAS Web Cache supports the POSIX 1003 extended regular expressions for URLs, as supported by Netscape Proxy Server 2.5.
|
See Also::
|
In a distributed cache hierarchy, an Oracle9iAS Web Cache server that caches content from a central cache to serve local requests. When an invalidation request is sent to the central cache, the central cache propagates the request to the remote cache, ensuring consist content.
A proxy server that appears to be a normal server to browsers but internally retrieves its documents from other origin servers as a proxy.
A protocol developed by Netscape Corporation. SSL is an industry-accepted standard for network transport layer security. SSL provides authentication, encryption, and data integrity, in a public key infrastructure (PKI). By supporting SSL, Oracle9iAS Web Cache is able to cache pages for HTTPS protocol requests.
Cacheability can be evaluated against the following attributes:
The process of binding a user session to a given origin server in order to maintain state for a period of time.
A cookie that enables a Web site to keep track of user sessions.
HTML hyperlink tags, such as <A HREF=...>, that contain embedded session information to distinguish users. You can configure Oracle9iAS Web Cache to substitute the values of session parameters in HTML hyperlink tags with the session information contained within a session cookie or an embedded URL parameter.
In an ESI cache hierarchy, an Oracle9iAS Web Cache server that assembles ESI content by contacting a provider cache for the template's HTML fragments. The HTML fragments are then assembled. When provider site content becomes invalid, the provider site propagates the invalidation request to the subscriber cache to ensure consistency.
The address syntax that is used to create a URL.
A standard for specifying the location and route to a file on the Internet. URLs are used by browsers to navigate the World Wide Web and consist of a protocol, domain name, directory path, and the file name. For example, http://otn.oracle.com/products/ias specifies the location and path a browser will travel to find the Oracle Technology Network's Oracle9i Application Server site on the World Wide Web.
See Uniform Resource Identifier (URI).
See Uniform Resource Locator (URL).
Expiration time, invalidation time, and removal time of a document.
Oracle9iAS Web Cache calculates validity by comparing the current time relative to an object's expiration/invalidation time and the object's scheduled removal time. Prior to expiration/invalidation time, the object is considered valid. Between expiration/invalidation time and removal time, the object's validity level decreases linearly. During this interim state, objects with a higher validity level have a higher propensity to be served stale. When current time reaches removal time, the object is considered totally invalid and can no longer be served stale. Scheduled removal time is something that administrators can control. When expiring/invalidating content, administrators have the option to remove objects immediately, which may be necessary for sensitive objects that should never be served stale. Likewise, where some degree of inconsistency is tolerable, administrators can specify a removal time in the near future.
A site hosted by Oracle9iAS Web Cache. Browsers can request cached content from these sites through Oracle9iAS Web Cache In addition to caching content, Oracle9iAS Web Cache can also assemble ESI fragments from these sites.
A transparent database used to manage authentication data such as keys, certificates, and trusted certificates needed by SSL. A wallet has an X.509 version 3 certificate, private key, and list of trusted certificates.
The percentage of the available capacity that the origin server can accept.
|
 Copyright © 2002 Oracle Corporation. All Rights Reserved. |
|
