Abstract: Apparatus for performing a data transaction, including at least one storage device which is adapted to receive data as a succession of data blocks for storage at respective physical locations therein and control circuitry. The control circuitry is configured to convey the succession of data blocks to the at least one storage device while writing to the at least one storage device, together with at least some of the data blocks, parameters indicative of the identity of the data transaction, the identity of the recorder of the transaction state, and a location of a subsequent data block in the succession. The control circuitry is also configured to transform a state of the data so as to complete (commit or abort) the data transaction using some of the indicative parameters. In the event of a failure of the apparatus before a transaction is completed, i.e., committed or aborted, the apparatus facilitates complete recovery using data stored in the data blocks.

Abstract: Apparatus for electronic data storage, including a non-volatile memory, adapted to receive a succession of data blocks for storage at respective locations therein. The apparatus includes a controller which is configured to convey the succession of data blocks to the non-volatile memory, while writing to the non-volatile memory, together with at least some of the data blocks, a pointer value to the location of a subsequent data block in the succession. The apparatus preferably includes services that are usually performed by higher level file systems, such as allocation and deletion of blocks. Furthermore, the apparatus facilitates stable storage operations so that block contents are maintained intact in case of a write failure.

Abstract: The invention is a system and method for establishing a communication connection between two programs, each running on multiple processors of a distributed or shared memory parallel computer, or on multiple computers in a cluster of workstations or a set of network connected workstations. The invention includes all protocols that require one of the two programs that wish to communicate to actively initiate the communication session, while the other program passively accepts such direct communication session initiations. No task of the active program of the connection will attempt to communicate with tasks of the passive program until after it has been notified that all passive program tasks are prepared to receive messages, and that all other active program tasks are prepare to receive messages from the passive programs tasks, and vice versa.

Abstract: Data transmission system comprising a single transmitter and a plurality of receivers and in which the transmitter sends a group Gi of data items to the plurality of receivers over a one-way channel, wherein each data item to be transmitted is divided in blocks which are encapsulated to form datagrams, each datagram including a block sequence number, a data item identifier, a timestamp reflecting the age of the data item, and a group directory GD is regularly sent by the transmitter) to each one of the plurality of receivers, the group directory containing information for all groups Gi of data items being sent enabling each one of the plurality of receivers to select the group of data items it wants to receive.

Abstract: In a multicasting system content is multicast from a sender to a plurality of receivers over a data network. Each receiver independently determines whether it is missing elements or packets of the content. Receivers having missing content each initiate a random timer. The receiver having the shortest random interval unicasts a negative acknowledgement to the sender, which immediately multicasts the negative acknowledgement to the other receivers. All other receivers having the same missing packet thereupon suppress their own negative acknowledgements as to that packet. A repair transmission is then multicast by the sender to all receivers. The random intervals have upper and lower bounds according to the round trip transmission time and the size of the largest missing data element.

Abstract: The invention is a system and method for establishing a communication connection between two programs, each running on multiple processors of a distributed or shared memory parallel computer, or on multiple computers in a cluster of workstations or a set of network connected workstations.

Abstract: A data transmission system, including a plurality of transmitters for transmitting a stream of multiplexed packets over a broadband channel, the packets being constructed from a stream of variable length data blocks, each of the blocks originating from different sources. The system also includes a plurality of receivers for receiving the stream of packets from the broadband channel and reconstructing the stream of variable length data blocks. The data blocks are distributed over one or more packets. The packets also include a packet header having a source identifier (SID) for identifying the source of the packet, and the first of the packets further including a block header having a block identifier (BID) for identifying the data block being transmitted.

Abstract: A caching arrangement for the content of multicast transmission across a data network utilizes a first cache which receives content from one or more content providers. Using the REMADE protocol, the first cache constructs a group directory. The first cache forms the root of a multilevel hierarchical tree. In accordance with configuration parameters, the first cache transmits the group directory to a plurality of subsidiary caches. The subsidiary caches may reorganize the group directory, and relay it to a lower level of subsidiary caches. The process is recursive, until a multicast group of end-user clients is reached. Requests for content by the end-user clients are received by the lowest level cache, and forwarded as necessary to higher levels in the hierarchy. The content is then returned to the requesters. Various levels of caches retain the group directory and content according to configuration options, which can be adaptive to changing conditions such as demand, loading, and the like.

Abstract: A data packet header including an internet protocol (IP) header, a remote direct memory access (RDMA) header, and a transmission control protocol (TCP) header, wherein the RDMA header is between the IP header and the TCP header.

Abstract: A method and system for transmitting data along one or more communication channels to a receiving device having addressable memory units, the data having a known size and being split into two or more data packets each having a respective header and each sent along one of said communication channels to a respective memory unit. A respective final data packet to be sent along each communication channel is marked so as to be identifiable by a respective memory unit. For each memory unit receiving the respective final data packet, an interrupt is generated, the receiving device is informed how much data was received by the memory unit, and a cumulative amount of data received by all memory units is determined so as to allow the reading device to identify when no more data packets are to be transmitted.

Abstract: A computer system such as a mobile client system in which provision is made for management of flash memory. Flash memory management is done using variable block length and supports data compression. Blocks are allocated contiguously in each erase unit and each block starts with a header that contains the length of the block. Blocks are tracked using a single-level virtual address map which resides in random access memory (RAM). The mobile computer system may also include a housing, processor, random access memory, display and an input digitizer such as a touchscreen.

Abstract: In a resilient database system which includes a journaled database which is implemented at one or more locations within a distributed data processing system, multiple diverse consistency levels are specified which each detail a level of consistency to be maintained between a primary database and a replica database. A user is then permitted to select a particular level of consistency for each replica database. Thereafter, each update to a record within the primary database is utilized to initiate an update to the corresponding record within each replica database in a manner which is consistent with the selected level of consistency for that replica database.