Abstract: A system and method for checkpointing a primary computer process to a backup computer process such that if there is a failure of a primary process, the backup process can takeover without interruption. In addition, upgrades to different version of software or equipment can take place without interruption. The invention provides a lightweight checkpointing method that allows checkpointing of only external requests or messages that change the state of the service instance, thereby reducing the overhead and performance penalties. In addition, the present invention checkpoints data for primary and backups that do not share resources but are logically equivalent. All communication between the primary and backup takes places using network protocols.

Abstract: A control module (100) includes a first signal processing unit (102) that is coupled to a second signal processing unit (114) by a control bus (130), an address bus (131) and a data bus (132). The control module conveys seed value addresses (108) and expected result addresses (110) over the address bus, seed values (118) and verification set output values (107) over the data bus, and compares each verification set output value to an expected result (120), thereby allowing the control module to determine whether the first signal processing unit, the control bus, the address bus, and the data bus are collectively functioning correctly. By properly selecting the seed value addresses, expected result addresses, seed values, and expected results (and correspondingly, verification set output values), proper operation of each line of the address bus and control bus may be individually verified.

Abstract: A computing system implements a SAN attached automated Hierarchical Storage Library with diverse media types and media failover capability where storage communications destined for any one media type may be redirected to another media type for uninterrupted storage communications with a host system when a failover condition has occurred. A preferred embodiment comprises: a) a controller network interface for connecting the storage area to a network; b) at least one control unit for HDD and removable media emulation; c) a failover bridge for seamless protocol conversion between media types; d) an HDD interface for connection to a plurality of HDD's on at least one backplane; e) at least one dual redundant controller component with dual mirrored NVRAM's thereby providing dual primary and failover communications links for the plurality of HDD's and removable media drives; f) a removable media interface for a plurality of removable media or removable media emulators.

Abstract: The present invention relates to highly available sequence number generation with minimal latency. The present invention involves establishing a primary and secondary sequence number generators. A sequence number request is forwarded to the primary generator. The primary generator determines the next sequence number and forwards the response to the secondary generator. The secondary generator stores the value and forwards the value to the originating entity. Accordingly, the configuration avoids single point failure and is robust against malfunction.

Abstract: An integrated circuit or other type of digital system including multiple processors is tested using a control mechanism which dynamically defines a group of processors subject to common control. The control mechanism receives one or more commands for each of the processors in the group, and delays issuance of one or more of the commands for the group until a designated group scan command is received for each of the processors in the group. The control mechanism may be in the form of a software-implemented chain manager which provides the above-noted group definition, command receipt and issuance delay operations, and subsequently delivers one or more of the test commands as a single serial bit stream to an IEEE 1149.1 hardware scan chain associated with the processors. The control mechanism can provide synchronous control for a group of homogeneous processors of the digital system, or pseudo-synchronous control for a group of heterogeneous processors of the digital system.

Abstract: Data blocks lost at a primary mass storage are restored while allowing the primary computer system to access the lost data block before full restoration. Restoration occurs along two channels. In the first channel, read requests issued by the primary computer system are handled by obtaining the requested data block from the backup mass storage device. The retrieved data block is then written to the primary mass storage, thereby restoring the primary mass storage for that data block. In the second channel of restoration, a snapshot copy of a selected data set of the backup mass storage is made and transported to the primary system. If the corresponding data block in the primary mass storage has a current data block, the data block is not written from the snapshot copy to the primary mass storage. Otherwise, the data block is copied from the snapshot copy to the primary mass storage.

Abstract: An electronic control system has a plurality of mutually networked or communicating control units, with special, redundant safeguarding measures during transmission of a safety-related transmitted signal from a first control unit to a second control unit. The first control unit generates the transmitted signal and a second signal complementary thereto on different paths, and sends them to a memory, together with two additional signals which are significant for the paths. A third control unit reads out the transmitted signal and the second signal from the memory, and checks them, and, upon detection of an error, switches off the first control unit or, given correct signals, generates different types of test or safety signals and conducts them to a memory.

Abstract: A method and system for tracking frequently occurring fail events that are detected during testcase simulation of a simulation model within a batch simulation farm in which testcases are executed within respect to a simulation model on one or more simulation clients. In accordance with the method of the present invention, the instrumentation server receives fail event packets from one or more simulation clients. The fail event packets contains an aggregate of detected occurrences of a specified fail event. The instrumentation server monitors the rate of occurrence of the specified fail event from received fail event packets to detect an excess rate of occurrence of the specified fail event.

Abstract: Presently preferred embodiments of the current invention are directed to a protocol analyzer for interpreting data frames captured on a communications network. The protocol analyzer includes a network interface connection for providing the electrical and physical connection to the communications network and for receiving data frames from the network in a particular physical layer protocol format. The protocol analyzer further includes analysis software for providing an interpretation of received data frames. The interpretation of a frame is based upon a series of definition constructs that are stored in a protocol definition file and a protocol database of the protocol analyzer. The definition constructs collectively define the characteristics of a data frame for a given physical layer protocol. Also, the constructs provide a means for identifying any one of a number of higher level protocols that may be embedded within the data frame.

Abstract: A method and apparatus for testing by sampling vectors circuit modules designated as channel models or as control modules and containing scan chains. Use is made of a test register which provides at least one control sampling mode signal for control modules and furthermore provides at least one channel sampling mode signal for channel modules. Channel modules and control modules can occur as circuit modules multiply with identical scan chains, enabling efficient testing in a manner that saves memory space. A logic is designed for the read-out of sampling output signals after testing of the scan chains via a read-out terminal unit of a test device, thus providing a comparison with desired sampling output signals for channel modules or for control modules in a comparator unit.

Abstract: A method and a device for monitoring data and the transmission of data between at least one first control unit and one second control unit are provided. The at least two control units have a first program level, to which are allocated programs which calculate the control function, as well as a second program level including programs that monitor the functional reliability of the programs of the first program level. The first control unit is connected to at least one component which may be used to acquire data, for example, controlled variables. The data acquired by the component or further data determined with this data may be transmitted from the first control unit to the second control unit over a single connection in a secure manner, and the data and the data transmission are secured separately in the first and second program levels such that errors in the data and the data transmission may be detected.

Abstract: A method, apparatus, system, and machine-readable medium to bound data transmission latency by transmitting error verification data at a point during a data transmission based upon loading of a channel for the data transmission is provided. Embodiments may comprise determining the loading of a communication channel and transmitting error verification data to a target device based upon the loading. More specifically, some embodiments transmit error verification data at intervals, variable intervals in some embodiments, to balance transmission latency against the bandwidth available from a communication medium.

Abstract: A method of verifying that a disc recording and reproducing apparatus normally analyzes defect management area (DMA) information in a read or write mode, and a test apparatus for performing the method. The method includes operating the recording and reproducing apparatus in a read or write mode, using a test disc with test reference information, and checking whether the recording and reproducing apparatus operates in the read or write mode to verify the DMA information analyzing function of the recording and reproducing apparatus. Accordingly, a DMA information analyzing function of the disc recording and reproducing apparatus in the read or write mode can be tested.

Abstract: A method, device, and system for automatic fail over of system controllers. A system controller includes a processor, a memory, and a plurality of I/O controllers. Each I/O controller is configurable with a plurality of I/O connections to another system controller. Each of the plurality of I/O controllers is further configurable with an I/O connection to each of one or more monitored devices. The method includes booting a plurality of system controllers configured as a primary system controller and at least one secondary system controller and booting one or more domains in the computer system from the primary system controller. The method also includes updating a system configuration on the primary system controller and updating the system configuration on the secondary system controller from the primary system controller.

Abstract: A system and method that uses a process management console to maintain multiple processes that perform software services from within a presentation layer and a database layer. The method includes defining an active process list for a plurality of processes that provide services in the presentation and database layers. Another step is monitoring the plurality of processes that are active in the presentation and database layers by using a process monitor. The next step is determining when one of the processes has abnormally terminated, using the process monitor to periodically compare the active process list to the list of processes currently executing. When a process fails, the system reactivates the process under the automatic control of the process monitor, and the reactivation is performed automatically. The system can also generate an error message that is logged or sent as an email to support personnel when a process has failed.

Abstract: A method and apparatus for detecting a change in the operational status of a first host computer and automatically configuring a second host computer to provide additional computing resources that replace or complement the first host computer. In one embodiment, a controller is provided that is capable of detecting a malfunction or failure of the first computer and automatically configuring a second host computer to replace the first host computer. In another embodiment, the controller is capable of detecting changes in the performance of the first host computer and automatically configuring a second host computer to provide additional computing resources for the first host computer. In a further embodiment, both of these techniques can be used to support an electronic commerce site and provide the electronic commerce site with failsafe operation and virtually unlimited computational resources.

Abstract: A semi-automated availability-assessment system and methodology. A comprehensive questionnaire providing detailed information about the hardware and operating-system components and configuration of a system, application-and-database-software components and configuration of the system, data related to other potential sources of unplanned downtime, and data related to potential sources of planned downtime is received. The information contained in the received questionnaire is processed in several steps. First, hardware and operating-system-component-and-configuration information is extracted in order to conduct a Markov-chain availability analysis of the overall system hardware and operating system to provide a first intermediate result.

Abstract: A method 20 and computer apparatus for using available firmware flash ROM space as a diagnostic drive. The computer apparatus has a nonvolatile random access memory, an Extensible Firmware Interface (EFI) and a basic input and output system (BIOS). To implement the functionality provided by the present invention, a command shell of the EFI is modified to include the EFI driver and operates to configure available flash space normally reserved for firmware (BIOS) as a diagnostic disk drive. The modified EFI and the EFI driver are stored in the flash memory. When the computer system 10 is initialized (booted), the EFI driver configures the available space in the flash memory that is not allocated to the firmware as the diagnostic disk drive. Diagnostic programs are loaded into the diagnostic disk drive, which are selectively run by a user, such as by using the command shell.

Abstract: A system and method for configuring a control plane within a network device. One of a pair of control processors is selected to act as the master of the control plane and the other control processor is specified as a standby control processor in normal operation. In the case of a failover or switchover event, the standby control processor assumes the role of the master of the control plane and updates configuration information within line cards in the network device as necessary. A state machine within the control processor is employed to manage state transitions for the control processor. Each control processor generates at least one signal that indicates whether it is capable of serving as the master of the control plane. Master selection logic selects one of the control processors as the master for the control plane and in one embodiment advertises the identification of the master control processor via triply redundant signals.

Abstract: A method, computer program product, and data processing system for analyzing trace data containing bus transactions taking place in packets of varying length is disclosed. A dump of raw trace data from a logic analyzer is stored in a computer file. A computer program then analyzes the raw trace data to identify the locations of packets within the raw trace data. A packet type is determined for each packet, and data fields are extracted from the packet, according to the packet type. A summary of each packet containing the data fields and their contents is then presented to a user.