754 results about "Asynchronous data" patented technology

A system and method for improving the efficiency of the transmission of updated blocks generated by logging all the block allocations and deletes as well as CPs and PCPI creation and deletion in a persistent log. The log is scanned during each update cycle (in which changes are transmitted to a destination mirror) by the storage operating system, and only changed blocks that are referenced by the file system as it existed at the end of the update cycle or referenced by PCPIs that existed at the end of the update cycle are actually sent in the transmission. This reduces the number of changes being transmitted.

A method of recovery from a data storage system failure in a data storage system having a host computer writing data updates to a local storage controller at a local site. The local controller is associated with a local storage device. The local storage controller is also configured to asynchronously copy the updates to a remote storage controller associated with a remote storage device at a remote site. In addition, the remote storage controller is configured to store a consistent point in time copy of the updates on a backup storage device. The consistent point in time copy is known as a consistency group. Upon detection of a failure associated with the local site, a determination is made whether a group of updates pending for storage on the backup storage device form an intact consistency group. If an intact consistency group has not formed, corrective action may be taken to create an intact consistency group. The recovery method further consists of synchronizing the remote storage device, initiating recovery operations and, upon recovery of the local site, resynchronization of the local storage device and the backup storage device to recovery consistency group without the need for full volume storage copies and while minimizing application downtime.

Write order fidelity (WOF) is maintained for totally-active implementations wherein a plurality of access nodes at geographically separated sites can concurrently read and/or write data in a “totally active” fashion on a distributed data system. From the hosts' perspective at diverse geographic locations, a synchronous, cache-coherent view of data is provided. Data transfer is asynchronous. A time ordered data image is created and maintained so operations can be restarted after a partial system failure that causes loss of data not yet asynchronously transferred across the network, but that has been write-acknowledged to the originating host. Time ordered asynchronous data transfer is implemented as a pipeline of changes that reflect contributions from all nodes. WOF also improves network performance and lowers bandwidth consumption. Extensions can provide, in a totally-active context, features such as point-in-time snapshots, time firewalls, on-demand backend storage allocation, synchronous/asynchronous distribution of data, and continuous data protection.

Examples of local communication systems are disclosed, based on a ring of point-to-point links, providing for transport of fixed rate synchronous, fixed rate asynchronous data and variable rate data in a flexible format. Different segments of the ring network can carry data at different bit rates, while remaining synchronized to a common frame rate and having a common control channel structure, for compatibility with earlier systems. Parallel channels are provided, either permanently or when required, for signalling errors of source data, data validity/padding, flow control. Parallel variable width channels are defined with free content (stream or packet). Null data symbols are defined for padding on a byte-by-byte basis. The allocation of capacity among variable width channels is revised block by block, and a transition period is defined to allow for ring latency. Calculations for allocation of capacity are performed during one block for the next block, locally at each source station, according to predetermined rules. Information as to bandwidth requirements is exchanged prior to the calculation via a special connection signalling channel and message format.

An asynchronous hypertext messaging system and method are disclosed. The system and method use existing hypertext transfer protocols and is capable of transmitting real-time asynchronous data between server and client regardless of firewalls or proxy servers implemented at the client or the server. In a communication system comprising a client and server interconnected by an internet, initial authentication is performed initially between the server and the client. A secure log in is performed by the client with the server in conjunction with a possible java applet download. The communication server then initiates a multiplexed virtual connection between the server and the client and transmission of asynchronous real-time data can occur over the virtual connection. The virtual connection is periodically refreshed by a request issued from the java applet.

An improved method for providing parallel apply in asynchronous data replication in a database system is disclosed. The improved method and system provides a high speed parallel apply of transactional changes to a target node such that the parallel nature of the application of changes does not compromise the integrity of the data. The method and system detects, tracks, and handles dependencies between transaction messages to be applied to the target node. If a transaction message has a dependency on one or more preceding transaction messages whose applications have not yet completed, that transaction message is held until the application completes. In addition, the method and system requires significantly less overhead than conventional approaches.

A system and method of lightweight asynchronous data replication that avoids the need for any persistent store at the replication source or communication channel, and is independent of the underlying data formats, wherein the method of data replication comprises replicating deltas from a source, embedding replication tracking information in the replicated deltas, wherein the tracking information comprises a timestamp and a sequence number, and applying deltas at a target. The tracking information is used to ensure that each delta is applied exactly once. In the event of a crash in the system, the target analyzes the tracking information to determine which deltas have been applied, and requests retransmission of replicated data from the source starting from the earliest unapplied delta. The source and target are treated as only delta producers and consumers, and as such the invention is applicable to replication between arbitrary data source formats.

A distributed Internet Protocol (IP) voting system and method for use in Land Mobile Radio (LMR) Systems having a central send-and-receive site and one or more receive-only sites. In the distributed voting system, receive-only sites are directly linked to the control point using a network and associated packet transmission protocol. This may be a high-speed asynchronous data link such as a standard IP network link. Each remote site receiving digital data, calculates a bit error for that data. This error calculation is incorporated into the data header information. The data header information and data are placed in an IP packet and transmitted as a User Data Protocol (UDP) message to the control point. The control point selects the lowest bit rate data message, or the first control message, and retransmits it using a standard radio air interface protocol, such as the APCO Project 25 air interface protocol.

Embodiments of the present invention provide techniques for managing content updates for web-based applications. In one set of embodiments, a configurable proxy cache is provided that executes rule-based content updates of web content on the behalf of an application (e.g., web browser) while the application is not running. This allows for better management of intermittent connection quality, memory/power savings for mobile devices, and caching of information that can be shared with the application and other network-aware applications/services. In various embodiments, the proxy cache is controlled by the application via standard web language constructs such as HTTP headers, thereby enabling interoperability with web-based applications that implement common asynchronous data-loading technologies.

A data mining system for a database management system and method and computer program product therefore, that provides improved functionality over synchronous data mining systems, and which provides features such as interruptible tasks and status output. A data mining system for a database management system comprises a plurality of data mining task objects operable to perform data mining functions, a data mining task queue table operable to maintain at least one queue to manage execution of the data mining tasks, and a data mining system task monitor operable to monitor execution of currently executing data mining tasks, examine the data mining task queue table, select at least one task for execution, dequeue data mining tasks from the data mining task queue table, and initiate execution of the dequeued tasks.

A system and method for creating and using configuration diagrams for configuring distributed systems. The methods described herein may be used for various types of operations in configuring distributed systems, including creating programs, managing programs in the distributed system, deploying programs to various distributed devices, configuring remote execution or inter-operation of distributed programs, and executing distributed applications. Embodiments of the invention utilize graphical iconic-based techniques for performing the above operations. The configuration diagram may include device icons which represent devices and program icons which represent programs. Device icons and program icons may be associated with each other to accomplish various program creation and deployment operations. Device icons and program icons may also interact with graphical program nodes or icons. Context sensitive device connections and/or program connections are displayed. An asynchronous data flow node may be used to facilitate asynchronous data flow between two graphical programs. The distributed system may also support distributed graphical debugging.

A multiple access telecommunication system is provided, which makes use of chaotic signals. Each transmitter has a chaotic system, which has at least one strange attractor in its phase space, and each receiver has chaotic systems, which corresponds to those in the transmitters from which it may receive signals. Each pair of users is assigned a set of periodic unstable orbits from a strange attractor, which that pair of users may use for signalling. At the transmitter side, a multiplexer receives data from plurality of users. These data are multiplexed in time, to produce an asynchronous data stream. The data stream is then mapped to a sequence of chaotic signals, in accordance with the set of trajectories for each transmitter and receiver pair.

A computer readable medium includes executable instruction to compare databases. The executable instructions are configured to identify when a segment of a first database is conditionally out of synchronization with a corresponding segment of a second database to establish a conditionally out of synchronization state at a first time. Executable instructions allow a latency period after the first time in which changes are made to the first database and the second database. Executable instructions also determine after the latency period whether the segment of the first database is in synchronization with the corresponding segment of the second database. Executable instructions also populate a resynchronization table, which is used by a replication mechanism to bring asynchronous rows into synchronization.