Abstract: A system and method are provided for maintaining states for user sessions with a web system. Maintaining state includes receiving a request from a user that initiates a user session with the web system and processing the request to provide a web page to the user. Session data (220) representing a state of the user session is stored in memory in a global session server (212). Then, for each subsequent request associated with the user session, the subsequent request is received, and the session data (220) is retrieved from the global session server (212). The subsequent request is then processed using the session data (220) to provide a web page to the user, and the session data (220) is changed to reflect the processing. The session data (220) is then updated in the global session server (212). The global session server (212) thereby stores session data (220) unique to each user session accumulated over multiple web transactions.

Abstract: An enterprise interaction hub (10) is disclosed which includes a number of layers that interact to manage an enterprise web system. An interaction layer (12) receives requests to the enterprise web system and returns responsive web pages. A presentation layer (14) is coupled to the interaction layer (12) and generates the responsive web pages. A business layer (16) is coupled to the presentation layer (14) and provides business logic for use by the presentation layer (14) in generating the responsive web pages. An integration layer (18) is coupled to the business layer (16) and interfaces with existing legacy data to provide the legacy data to the business layer (16). A trend collection layer (32) monitors and accumulates historical information from the interaction layer (12), the presentation layer (14), the business layer (16) and the integration layer (18). The trend collection layer (32) also stores the historical information in a trend database (36).

Abstract: An enterprise interaction hub (10) is disclosed which includes a number of layers that interact to manage an enterprise web system. An interaction layer (12) receives requests to the enterprise web system and returns responsive web pages. A presentation layer (14) is coupled to the interaction layer (12) and generates the responsive web pages. A business layer (16) is coupled to the presentation layer (14) and provides business logic for use by the presentation layer (14) in generating the responsive web pages. An integration layer (18) is coupled to the business layer (16) and interfaces with existing legacy data to provide the legacy data to the business layer (16). A trend collection layer (32) monitors and accumulates historical information from the interaction layer (12), the presentation layer (14), the business layer (16) and the integration layer (18). The trend collection layer (32) also stores the historical information in a trend database (36).

Abstract: A system and method are provided for maintaining states for user sessions with a web system. Maintaining state includes receiving a request from a user that initiates a user session with the web system and processing the request to provide a web page to the user. Session data (220) representing a state of the user session is stored in memory in a global session server (212). Then, for each subsequent request associated with the user session, the subsequent request is received, and the session data (220) is retrieved from the global session server (212). The subsequent request is then processed using the session data (220) to provide a web page to the user, and the session data (220) is changed to reflect the processing. The session data (220) is then updated in the global session server (212). The global session server (212) thereby stores session data (220) unique to each user session accumulated over multiple web transactions.

Abstract: A method for logging transactions which alters a file system stored on a secondary storage device is disclosed. The method includes the steps of writing data to a buffer in a buffer cache and logging the transaction in a log buffer residing on a primary storage device. A flag is set for the modified buffer, which is then added to a list of modified buffers. As the log buffer becomes substantially full, its contents are copied to a log partition residing on the secondary storage device. After an abnormal system shutdown, the contents of the log partition are copied to the buffer cache in order to restore the disk filing system.

Abstract: A virtual memory system groups pages into clusters according to use, determined by first reference and frequency of reference. The virtual memory system comprises a random access memory and an auxiliary memory. A central processing unit the virtual memory system with an address. Whenever that address identifies a memory location not stored in the RAM, the entire cluster of pages in which the address is located is retrieved from the auxiliary memory into the random access memory.

Abstract: A system for dynamically allocating memory to a file buffer cache manager and a virtual memory space manager is provided. The file buffer cache memory is time stamped at times of acquisition and access, and the acquired virtual memory space memory is time stamped at times of acquisition and access. If the file buffer cache manager or the virtual memory address manager requests memory, the time stamps of the memories acquired by the file buffer cache manager and the virtual memory space manager are compared. The piece of memory which has the earlier time stamp is preempted and allocated to the manager which has requested memory.

Abstract: A memory management system for a digital computer divides a virtual memory space into regions. Each region has attributes indicating generation, volatility, and activity. During garbage collection, memory objects referenced by normal program execution are copied to regions having an active attribute. Objects copied as a result of garbage collector scavenger action are moved to regions which are inactive. Increasing levels of inactivity are provided in different regions. Grouping of active objects into active regions causes a large proportion of main memory to contain only active objects, which minimizes paging and increases system performance.

Abstract: A garbage collection system for digital computers classifies memory objects into generations. Objects in older generations which need to reference younger generations must do so indirectly through indirection cells located in the older generation. Thus, all pointers into a generation come from younger generations or indirection cells. When a generation is collected, the indirection cells in that generation are defined to be oldspace and collected in the usual manner. Indirection cells of older generations which can point to the generation being collected are processed by a scavenger.The system also includes read and write barriers which function to filter out undesirable pointers based on the classification and volatility of memory regions to which they point or are destined to be stored.