Abstract: A system and method for dynamically selecting a level of compression to be applied to data to be served to a client. The level of compression may be selected on the basis of one or more factors, such as: the bandwidth of a communication link between the client and a server, the amount of data requested by the client, the workload of the server, whether the data are cacheable, etc. The server can readily obtain information such as the amount of requested data and the available CPU time on the server. To determine the bandwidth, the server may conduct a test transfer of a known amount of data to or from the client, or consult a database identifying known or expected bandwidths for specific client connections (or addresses). Based on the selected factor(s), the server dynamically selects a level of compression for the data.

Abstract: A test probe tip constructed substantially from resistive material. The resistive material is made of resistive conducting material substantially enclosed in and dispersed throughout encapsulating material. The test probe tip has a probing end for probing electronic circuitry and a connection end for interfacing with a probing head. The resistive conducting material forms at least one path through the encapsulating material from the probing end to the connection end. The resistive conducting material may be a plurality of longitudinally-extending resistive/conductive members or a plurality of particulate resistive/conductive members.

Abstract: A system and method for sharing images and collaborating in the selection of images likely to be interest to a user. Images (e.g., photos) are shared within a community of users, by allowing user to access any unrestricted community image, recommend an image to another user, assemble compilations of any images the user can access, etc. Various metrics regarding user activity are tracked, such as how often an image was viewed, downloaded, recommended, included in a compilation, printed, edited, etc. The metric values may be normalized, and then weighted and combined to produce, for each image, a ranking or rating personalized to an individual user. Ratings of images for a user may be used to order them for electronic presentation, assemble a set of images for an electronic compilation (e.g., an online album) or physical compilation (e.g., a photo book, a yearbook) or for some other purpose.

Abstract: A system and method for communicating a side effect of one data request, or other event, as part of a response to another data request or event. The side effect may include notification of the invalidation of cached data, from an upstream cache to a downstream cache. The upstream cache may store invalidation notifications as they are generated or received, and as responses to data requests are sent downstream, piggyback or merge one or more notifications with a response. This scheme avoids the need to open separate communication connections using specified invalidation accounts and passwords.

Abstract: A system and method for enabling a cache system, operating on behalf of a data server (e.g., web server, application server, database server), to serve one set of data in response to multiple requests that differ in content or form. In particular, the requests may include different session identifiers for identifying different users, clients or sessions, but they target the same basic set of data (e.g., a web page). When a set of data is cached in response to a request having one session identifier, it can also be served in response to another request having a second session identifier because the session identifiers are deleted, masked, replaced or otherwise ignored when searching the cache system for data responsive to the second request. Also, the cache system may include a requestor's session identifier as part of a data identifier (e.g., URI, hyperlink) within data served to the requester.

Abstract: A system and method for communicating a side effect of a data request, from a data server and through one or more caches, inline with a response to the request. Instead of sending a separate notification of the side effect (e.g., instructions to invalidate data cached in one or more caches), the notification is included in the response. As the response traverses caches on its way to the requestor, each cache applies the side effect with the proper timing. Thus, data invalidation may be performed prior to caching data included in the request and/or forwarding the response toward the requester. A final cache configured to serve the response to the requestor may remove the side effect notification before serving the response.

Abstract: A system and method for facilitating the invalidation of cached data, in which the data to be invalidated are identified using information other than a primary key. The primary key for a cached data object, such as a web page, may be a Uniform Resource Locator (URL). Instead of using an object's URL to identify to a cache the data to be invalidated, a secondary key is used, such as the object's data source or a template from which the object was created. An application communicates the secondary key to a cache, and the cache identifies cached objects that match the secondary key. Those data objects are then invalidated without having to issue multiple invalidation messages from the application.

Abstract: A system and method for detecting and managing user session meta-data at a reverse proxy server. The reverse proxy server is logically located between one or more origin servers and any number of users. The reverse proxy server detects the establishment and tearing down of a user session, and any expiration associated with the user session. The reverse proxy server identifies the creation of a session from the pattern and/or content of communications between a user and an origin server, and associates the user (e.g., by username or user ID) with the session (e.g., session ID or cookie). A user session table may be populated with an entry for each observed session. Tear down of a session may be detected by identifying an explicit user logout or a session termination by the origin server.

Abstract: A system and method for managing security meta-data in a reverse proxy server. The reverse proxy caches data served by an origin server, and also stores security meta-data for authenticating a user and/or authorizing access to cached data. The security meta-data may include an ACL (Access Control List), access control token or descriptor, other access control information, user credentials, user privileges or roles, group membership, user aliases, etc. The reverse proxy may automatically receive access control information from the origin server when a request for data is forwarded to the origin server, or may explicitly request the information from the origin server or a security server. The reverse proxy receives and applies invalidation messages to invalidate stored security meta-data. Also, the reverse proxy acts in a stateful manner, with knowledge of the correlation between a given user and that user's session with the origin server.

Abstract: A self-adaptive hybrid cache and method of caching data objects. A set of cacheable data objects is partitioned among a set of cooperating caches (e.g., a cache cluster). A hybrid cache is configured to cache data objects that it owns (i.e., objects in its partition) as primary content and to also cache data objects that are owned by other caches as secondary content (e.g., based on demand for such objects). A hybrid cache stores and/or removes objects based on criteria such as validity, popularity, size, age, cost of replacing, amount of available cache space, whether the objects are primary or secondary, etc. Over time, the amount or ratio of primary and secondary data that a hybrid cache stores may fluctuate dynamically.

Abstract: One embodiment of the present invention provides a system that facilitates serving data from a cache server. The system operates upon receiving a request for the data at the cache server. The system first determines if the request requires access control, and also if the data is available in the cache. If the request requires access control and if the data is available in the cache, the system sends an authorization request to an origin server. Upon receiving a response from the origin server, the system determines if the response is an authorization. If so, the system sends the data to the requester.

Abstract: A system and method for dynamically selecting a level of compression to be applied to data to be served to a client. The level of compression may be selected on the basis of one or more factors, such as: the bandwidth of a communication link between the client and a server, the amount of data requested by the client, the workload of the server, whether the data are cacheable, etc. The server can readily obtain information such as the amount of requested data and the available CPU time on the server. To determine the bandwidth, the server may conduct a test transfer of a known amount of data to or from the client, or consult a database identifying known or expected bandwidths for specific client connections (or addresses). Based on the selected factor(s), the server dynamically selects a level of compression for the data.

Abstract: A system and method are provided for automatically invalidating cached data. A cache system caches data from a data server (e.g., web server, application server, database). When a request is received at the cache system from a client, particularly a request to alter or replace a set of data, the request is examined and may be compared to a set of rules or data relationships that invoke automatic invalidation. Based on a pattern or content of the request (e.g., an identifier of data to be changed), the cache system identifies and invalidates a cached data item without waiting for the data server to receive the request, process it and instruct the cache system to invalidate the data item. In a cache system comprising multiple caches, one cache may notify another when automatic invalidation is necessary.

Abstract: A lossy dielectric device dissipates, absorbs and/or dampens electric fields. The lossy dielectric device may be used with any transmission path, such as a transmission line or resistor in a probe head. The lossy dielectric device preferably includes a lossy dielectric material contained within a container. The container is positionable and securable substantially adjacent said transmission path to improve the curve of a frequency response. Preferably, the container is insulative, puncture resistant, and thin. In some preferred embodiments, a temporary or permanent connection mechanism is also included.

Abstract: A test probe tip constructed substantially from resistive material. The resistive material is made of resistive conducting material substantially enclosed in and dispersed throughout encapsulating material. The test probe has a probing end for probing electronic circuitry and a connection end for interfacing with a probing head. The resistive conducting material forms at least one path through the encapsulating material from the probing end to the connection end. The resistive conducting material may be a plurality of longitudinally extending resistive/conductive members or a plurality of particulate resistive/conductive members.

Abstract: A system and method for facilitating the invalidation of cached data, in which the data to be invalidated are identified using information other than a primary key. The primary key for a cached data object, such as a web page, may be a Uniform Resource Locator (URL). Instead of using an object's URL to identify to a cache the data to be invalidated, a secondary key is used, such as the object's data source or a template from which the object was created. An application communicates the secondary key to a cache, and the cache identifies cached objects that match the secondary key. Those data objects are then invalidated without having to issue multiple invalidation messages from the application.

Abstract: A system and method for communicating a side effect of a data request, from a data server and through one or more caches, inline with a response to the request. Instead of sending a separate notification of the side effect (e.g., instructions to invalidate data cached in one or more caches), the notification is included in the response. As the response traverses caches on its way to the requestor, each cache applies the side effect with the proper timing. Thus, data invalidation may be performed prior to caching data included in the request and/or forwarding the response toward the requester. A final cache configured to serve the response to the requestor may remove the side effect notification before serving the response.

Abstract: A system and method for communicating a side effect of one data request, or other event, as part of a response to another data request or event. The side effect may include notification of the invalidation of cached data, from an upstream cache to a downstream cache. The upstream cache may store invalidation notifications as they are generated or received, and as responses to data requests are sent downstream, piggyback or merge one or more notifications with a response. This scheme avoids the need to open separate communication connections using specified invalidation accounts and passwords.

Abstract: A method and system are provided for caching data in a manner that substantially maintains a desired level of system performance. A cache server receives data requests on behalf of a data server. When new data on the data server is generated or stored that replaces or changes data cached on the cache server, the corresponding data on the cache server is invalidated. A subsequent request for the new data may be forwarded to the data server or may be served with the invalid data on the cache server. Determining how to serve the request may depend on a possible impact on system performance and/or one or more characteristics or parameters associated with the requested data. The impact on system performance may be determined by examining actual and/or desired operating conditions (e.g., rate or number of requests, load on the data server, response time to requests, number of open connections, throughput).

Abstract: A system and methods are provided for enabling a cache system, operating on behalf of a data server (e.g., web server, application server, database server), to cache and customize one set of data (e.g., a web page) in different ways for different requests (e.g., to include a client's name, account information, a special logo). An application that generates or produces the data on the data server embeds or includes special tags or markers in customizable data, to identify where custom data should be inserted or substituted. The custom data may be included in client requests or retrieved from the cache system, data server or elsewhere. When the cache system receives a new request for cached data that is customizable, the data is retrieved from cache, the custom data is retrieved and inserted at the corresponding tags and the customized data is served.