Abstract: A large distributed enterprise includes computing resources that are organized into one or more managed regions, each region being managed by a management server servicing one or more gateway machines, with each gateway machine servicing a plurality of endpoint machines. A method of diagnosing a fault in such an environment begins by deploying a management infrastructure throughout the computer network, the management infrastructure including a runtime environment at each of the endpoint machines. In response to occurrence of the fault, a software agent is selected, the software agent being executable by the runtime environment at an endpoint machine. The selected software agent is then deployed into the computer network to diagnosis the fault. If the location of the fault is indeterminate, the software agent migrates to the location by gathering information about the fault as it traverses the network.

Abstract: A routing apparatus is located at an outbound “edge” of an administrative domain or at an inbound “edge” of an ISP or other network facility. The apparatus, which is preferably implemented in software, includes a “dispatcher.” The dispatcher has a database associated therewith in which information about a “current state” of the network or some resource therein is collected and maintained. The “current state” information is generally of two types: quality-of-service (Q-o-S) information associated with transactions involving a particular Web server, or more general network resource availability information. According to the invention, a routing “policy” is defined at the dispatcher using at least one routing rule having a condition and an action. As service requests arrive at the dispatcher, each of the requests is routed to a destination by testing the current state information against the condition.

Abstract: A method of validating a request to access a target server in a computer network having an open, trusted database. The method begins when a request to access the target server is received at a host from which the scheme is supported. In response, a query is initiated to the trusted database to identify a technical, administrative or other contact person that may authorize the access request. In the Internet, the trusted database may be the WHOIS database that includes second level domain name information. A second query (e.g., an e-mail) is then launched to the identified contact. The e-mail preferably includes a URL and a key. The URL identifies a response Web page interface that is accessible upon entry of the key. If the identified contact accesses the Web page interface, he or she may then authorize the access request, deny the access request, or indicate under what conditions the request may occur.

Abstract: Data representing, for instance, an image is lossily encoded, and a residual of the data is losslessly encoded. The lossily encoded data and the losslessly encoded residual provide a losslessly compressed data representation of the original data. The losslessly compressed data is then organized and stored on a storage system according to one or more criteria selected for the particular losslessly encoded data to be organized. This enables the efficient retrieval and processing of the compressed data, including retrieval of portions of the compressed data.

Abstract: A communications facility for interactive communications with local applications. The flow of information to local applications is coordinated using a browser. The browser determines, at any given time, which of a plurality of communication paths is to be used to provide the information to the local application. The local application commences a polling loop, which enables messages to be received at the local application via the plurality of communication paths, without terminating the local application. Thus, the local application can have interactive communications with the browser and/or one or more remote servers.

Abstract: A method of identifying quality-of-service problems associated with a given Web server in a computer network. The Web server includes a Web page having a token declaring that quality-of-service information is to be collected. When the Web page is received at a Web client having the capability to collect the information, an indication is provided to the Web client user that the information is being collected. The collected quality-of-service information is then uploaded, preferably without any information identifying the user, either to the Web server that served the page or to a management server.

Abstract: Data representing, for instance, an image is lossily encoded, and a residual of the data is losslessly encoded. The lossily encoded data and the losslessly encoded residual provide a losslessly compressed data representation of the original data. The losslessly compressed data is then organized and stored on a storage system according to one or more criteria selected for the particular losslessly encoded data to be organized. This enables the efficient retrieval and processing of the compressed data, including retrieval of portions of the compressed data.

Abstract: A range of key values is partitioned into a plurality of key subranges equal in number to the number of record storage areas available for the sort. One of the key subranges is then assigned to each of the record storage areas and records to be sorted are transferred to the record storage areas in accordance with a sort key value within each record and the key subrange assigned to each of the record storage areas. Whenever a record is transferred to a filled record storage area, a record from the filled record storage area is transferred to an output string, namely the record that has the lowest key value that is not lower than the last record added to the output string of the filled record storage area.

Abstract: A task scheduler for use in a multiprocessor, multitasking system in which a plurality of processor complexes, each containing one or more processors, concurrently execute tasks into which jobs such as database queries are divided. A desired level of concurrent task activity, such as the maximum number of tasks that can be executed concurrently without queuing of tasks, is defined for each processor complex. Each job is assigned a weight in accordance with the external priority accorded to the job. For each job there is defined a desired level of concurrent; task activity that is proportional to its share of the total weight assigned to all concurrently executing jobs. The jobs are prioritized for execution of awaiting tasks in accordance with the discrepancy between the desired level of multitasking activity and the actual level of multitasking activity for each job.

Abstract: A plurality of queries (jobs) which consist of sets of tasks with precedence constraints between them are optimally scheduled in two stages of scheduling for processing on a parallel processing system. In a first stage of scheduling, multiple optimum schedules are created for each job, one optimum schedule for each possible number of processors which might be used to execute each job, and an estimated job execution time is determined for each of the optimum schedules created for each job, thereby producing a set of estimated job execution times for each job which are a function of the number of processors used for the job execution. Precedence constraints between tasks in each job are respected in creating all of these optimum schedules. Any known optimum scheduling method for parallel processing tasks that have precedence constraints among tasks may be used but a novel preferred method is also disclosed.