Abstract: A primary (e.g., master) file system stores multiple files and corresponding metadata. A view generator function receives template information (e.g., view configuration information) specifying types of metadata information associated with the multiple files stored in the primary file system. Based on processing of the metadata information in the primary file system as specified by the template information, the generator function produces metadata for inclusion in a secondary file system, which is used to satisfy search inquiries associated with the multiple files stored in the primary file system. According to one arrangement, the generator function replicates metadata information in the primary file system as specified by the template information for inclusion in the secondary file system. The secondary file system can include metadata from other sources as well that produced by the generator function.

Abstract: A multi-node computer network includes a plurality of nodes coupled together via a data link. Each of the nodes includes a local memory, which further comprises a shared memory. Certain items of data that are to be shared by the nodes are stored in the shared portion of memory. Associated with each of the shared data items is a data structure. When a node sharing data with other nodes in the system seeks to modify the data, it transmits the modifications over the data link to the other nodes in the network. Each update is received in order by each node in the cluster. As part of the last transmission by the modifying node, an acknowledgement request is sent to the receiving nodes in the cluster. Each node that receives the acknowledgment request returns an acknowledgement to the sending node. The returned acknowledgement is written to the data structure associated with the shared data item.

Abstract: A multi-node computer network includes a plurality of nodes coupled together via a data link. Each of the nodes includes a local memory, which further comprises a shared memory. Certain items of data that are to be shared by the nodes are stored in the shared portion of memory. Associated with each of the shared data items is a data structure. When a node sharing data with other nodes in the system seeks to modify the data, it transmits the modifications over the data link to the other nodes in the network. Each update is received in order by each node in the cluster. As part of the last transmission by the modifying node, an acknowledgement request is sent to the receiving nodes in the cluster. Each node that receives the acknowledgment request returns an acknowledgement to the sending node. The returned acknowledgement is written to the data structure associated with the shared data item.

Abstract: An error recovery method and apparatus has specific application in a networking arrangement having a plurality of individual processing nodes which communicate via shared memory space. For error recovery, the system uses a reliable error count, the value of which is maintained by all of the nodes. When an error is detected, the error count is incremented, and all of the active nodes are provided with the new error count. Any of the nodes can run the error recovery method, and may gain exclusive access to the network by acquiring an error recovery spinlock. Once the spinlock is acquired, the node holding the spinlock increments the error count and confirms that all active nodes have received the new error count. The spinlock is thereafter released.

Abstract: An apparatus for allocating data to and retrieving data from a cache includes a memory subsystem coupled between a processor and a memory to provide quick access of memory data to the processor. The memory subsystem includes a cache memory. The address provided to the memory subsystem is divided into a cache index and a tag, and the cache index is hashed to provide a plurality of alternative addresses for accessing the cache. During a cache read, each of the alternative addresses are selected to search for the data responsive to an indicator of the validity of the data at the locations. The selection of the alternative address may be done through a mask having a number of bits corresponding to the number of alternative addresses. Each bit indicates whether the alternative address at that location should be used during the access of the cache in search of the data.

Abstract: A monitor for monitoring the occurrence of events on the bus (15) of a multiprocessor computer system. The bus event monitor (BEM) includes a dedicated BEM processor (23) and an event counter subsystem (25). During each bus cycle, the BEM (21) captures and interprets the packet of data being transmitted on the bus (15). If the packet represents an event designated by the user to be of interest, a counter associated with the type of packet that was captured and interpreted is incremented by one. More specifically, a field programmable gate array (FPGA), configured by the user, defines the type of events to be counted. When an event to be accounted occurs, the FPGA (33) produces a counter address that is based on the nature of the event, and causes an enable pulse to be generated. The address is applied to the active one of two event counter banks (39a, 39b) via an input crossbar switch (37a). The enable pulse enables the addressed event counter to be incremented by one.

Abstract: A node includes logic circitry for transmitting and receiving data on a backplane bus. The driver in the transmitting logic in the node acts with the current source provided by the bus to decrease the transition time of the data transmitted onto the bus. A coupling resistor is included in the node for individually coupling the driver in the node to the bus for limiting voltage excursions on the bus and providing impedance matching between the node and bus and permitting driver overlap at the bus so that higher speed and lower power dissipation occurs. In the preferred embodiment, CMOS logic circuitry is utilized.

Abstract: A node for obtaining access to a bus. In this arbitration method, the node receives a conditional grant. The node determines whether access to the bus will actually transfer to it. The node contains distributed logic that examines an extend bus cycle signal to determine whether it can become a transmitter to transfer messages on the bus. When the node becomes a transmitter, it generates an extend bus cycle signal to maintain access to the bus when executing a multi-cycle transfer, even though other nodes, perhaps with higher priorites, require access to the bus.

Abstract: A computer system having multiple processors interconnected by a pended bus provides exclusive read-modify-write operations employing multiple lock bits. A processor generates an interlock read command which is transmitted as a transfer over the pended bus to a memory or I/O node. Acknowledge confirmations are transmitted by the memory back to the processor two bus cycles after each bus cycle of the processor transfer. The processor transfer, including an interlock read command, is stored in a input queue in memory and processes in turn by the memory. A first interlock read command to a specified memory location causes a lock bit to be set for that location and a first type of response message including the contents of the specified location to be generated by the memory and stored in an output queue.

Abstract: A node for obtaining access to a bus. In this arbitration method, the node receives a conditional grant. The node determines whether access to the bus will actually transfer to it. The node contains distributed logic that examines an extend bus cycle signal to determine whether it can become a transmitter to transfer messages on the bus. When the node becomes a transmitter, it generates an extend bus cycle signal to maintain access to the bus when executing a multi-cycle transfer, even though other nodes, perhaps with higher priorities, require access to the bus.

Abstract: A node for communicating with a plurality of other nodes in a computer, the node including logic circuitry for transmitting and receiving data at first and second logic levels. A default generator is connected to an arbiter and responds to a lack of request activity and the absence of a multi-cycle data transfer being performed on the bus and causes the bus to be driven to one of the first and second logic levels.

Abstract: A system and method for nodes to obtain access to a bus. In this arbitration method, a central arbiter selects a particular node and issues a conditional grant. The conditional grant is transmitted before it is determined whether access to the bus will actually transfer to another node. Each node contains distributed logic that examines an extend bus cycle signal to determine whether it can become a transmitter to transfer messages on the bus. When a node becomes a transmitter, it generates an extend bus cycle signal to maintain access to the bus when executing a multi-cycle transfer, even though other nodes, perhaps with higher priorities, require access to the bus.

Abstract: A memory node in a computer system having multiple processors interconnected by a pended bus provides exclusive read-modify-write operations employing multiple lock bits. A processor generates an interlock read command which is transmitted as a transfer over the pended bus to the memory node. Acknowledge confirmations are transmitted by the memory back to the processor two bus cycles after each bus cycle of the processor transfer. The processor transfer, including an interlock read command, is stored in a input queue in memory and processed in turn by the memory. A first interlock read command to a specified memory location causes a lock bit to be set for that location and a first type of response message including the contents of the specified location to be generated by the memory and stored in an output queue.

Abstract: A node for obtaining access to a bus. In this arbitration method, the node receives a conditional grant. The node determines whether access to the bus will actually transfer to it. The node contains distributed logic that examines an extend bus cycle signal to determine whether it can become a transmitter to transfer messages on the bus. When the node becomes a transmitter, it generates an extend bus cycle signal to maintain access to the bus when executing a multi-cycle transfer, even though other nodes, perhaps with higher priorities, require access to the bus.

Abstract: A processor node providing exclusive read-modify-write operations in a computer system having multiple processors interconnected by a pended bus and employing multiple lock bits. The processor generates an interlock read command which is transmitted as a transfer over the pended bus to a memory or I/O mode. Acknowledge confirmations are transmitted by the memory back to the processor two bus cycles after each bus cycle of the command transfer. The command transfer, including an interlock read command, is stored in an input queue in memory and is processed in turn by the memory. A first interlock read command to a specified memory location causes a lock bit to be set for that location and a first type of response message including the contents of the specified location to be generated by the memory and stored in an output queue.

Abstract: A multiple node computer system includes processor nodes, memory nodes, and input/output nodes interconnected on a pended bus. The system includes a lockout indicator which is set upon receipt of a locked response message by a processor node from a memory node in response to an interlock read command. The processors include a lockout check circuit responsive to the condition of the lockout indicator and will restrict generation of additional interlock read commands according to a predetermined access gating criterion until the lockout indicator is reset. In this manner, processor nodes of the system are assured equitable access to a memory node.

Abstract: A system for communicating between a plurality of nodes in a computer, each node including logic circuitry for transmitting and receiving data. The subject system includes (1) a backplane bus for carrying the data between the nodes, (2) a driver in each node and a current source circuit coupled to the bus which drive the bus in parallel to decrease the transition time of the data transmitted onto the bus, and (3) coupling resistors individually coupling the bus to the driver in each node and providing impedance matching between the bus and nodes and permitting driver overlap at the bus so that the higher speed and lower power dissipation occurs. In the preferred embodiment, CMOS logic circuitry is utilized and resistors are used to terminate the ends of the bus to the supply voltages.

Abstract: A computer system having multiple processors interconnected by a pended bus provides exclusive read-modify-write operations employing multiple lock bits. A processor generates an interlock read command which is transmitted as a transfer over the pended bus to a memory or I/O node. Acknowledge confirmations are transmitted by the memory back to the processor two bus cycles after each bus cycle of the processor transfer. The processor transfer, including an interlock read command, is stored in a input queue in memory and processes in turn by the memory. A first interlock read command to a specified memory location causes a lock bit to be set for that location and a first type of response message including the contents of the specified location to be generated by the memory and stored in an output queue.

Abstract: A system for communicating between a plurality of nodes in a computer, each node including logic circuitry or transmitting and receiving data at first and second logic levels. The system includes an arbiter coupled to the nodes for detecting a lack of request activity from the nodes. A default generator is connected to the arbiter and responds to a lack of request activity and the absence of a multi-cycle data transfer being performed on the bus and causes the bus to be driven to one of the first and second logic levels.

Abstract: An interface system between a high speed user bus and a system bus is provided to present to the user bus a picture of the data transferred on the system bus every clock cycle of that system bus. The interface system also allows the user bus to transfer data back to the system bus during selected bus cycles. By using a single pin connection to the system bus, the user bus can send communications back to itself by way of the system bus.