1380 results about "Fast recovery" patented technology

A cluster recovery process is implemented across a set of distributed archives, where each individual archive is a storage cluster of preferably symmetric nodes. Each node of a cluster typically executes an instance of an application that provides object-based storage of fixed content data and associated metadata. According to the storage method, an association or “link” between a first cluster and a second cluster is first established to facilitate replication. The first cluster is sometimes referred to as a “primary” whereas the “second” cluster is sometimes referred to as a “replica.” Once the link is made, the first cluster's fixed content data and metadata are then replicated from the first cluster to the second cluster, preferably in a continuous manner. Upon a failure of the first cluster, however, a failover operation occurs, and clients of the first cluster are redirected to the second cluster. Upon repair or replacement of the first cluster (a “restore”), the repaired or replaced first cluster resumes authority for servicing the clients of the first cluster. This restore operation preferably occurs in two stages: a “fast recovery” stage that involves preferably “bulk” transfer of the first cluster metadata, following by a “fail back” stage that involves the transfer of the fixed content data. Upon receipt of the metadata from the second cluster, the repaired or replaced first cluster resumes authority for the clients irrespective of whether the fail back stage has completed or even begun.

A new Fast Recovery Plus (FR+) mechanism, and associated method, for wireless and/or mobile network applications to control data flow and avoid network congestion in a TCP/IP packet-switched network.

A check valve which is positioned in the vacuum air line of an internal combustion engine. The check valve includes a single-piece valve body having an outlet port and two or more inlet ports, with one outlet port located substantially in line with the inlet port and connected by a venturi tube. The second inlet port is separated from the main air flow line by the valve stem and a diaphragm which allows communication there between and prevents back pressure. The second inlet port communicates with the outlet port through the valve stem and a second venturi tube which provides a vacuum boost to a device, usually vehicle brakes, connected to the inlet. The use of seal diaphragms having a non-constant radius allows for faster recovery time for replenishment than prior art devices.

Techniques for fast recovery and/or balancing of connections to a clustered computing system provide management of such connections by determining a number of connections to load balance across nodes and by triggering creation of such connections. In one aspect, a notification of an event regarding the clustered computing system is received by a connection pool manager, a pool of connections to the system is identified based on the notification, and one or more connections from the pool are processed in response to the event. According to an embodiment, the notification comprises the identities of the service, database, server instance and machine that correspond to the event.

A cluster recovery and maintenance system, method and computer program product for use in a server cluster having plural nodes implementing a server tier in a client-server computing architecture. A first group of N active nodes each run a software stack comprising a cluster management tier and a cluster application tier that actively provides services on behalf of one or more client applications running in a client application tier on the clients. A second group of M spare nodes each run a software stack comprising a cluster management tier and a cluster application tier that does not actively provide services on behalf of client applications. First and second zones in the cluster are determined in response to an active node membership change involving one or more active nodes departing from or being added to the first group as a result of an active node failing or becoming unreachable or as a result of a maintenance operation involving an active node. The first zone is a fault tolerant zone comprising all active nodes that remain operational. The second zone is a fault containment zone comprising all active nodes participating in the membership change and at least a corresponding number of spare nodes to the extent that the membership change involves a node departure. During recovery and maintenance, fast recovery/maintenance and high application availability are implemented in the fault containment zone, while continuous application availability is maintained in the fault tolerant zone.

A communication recovering system for a wavelength division multiplexed passive optical network (WDM PON). The communication recovering system can recover fault of optical fibers between the central office and the remote nodes without additional optical fibers by grouping two remote nodes and employing an AWG having periodic transmission characteristics, and can also simply and rapidly recover such a fault with minimal optical loss using an AWG of 2×N structure and an On-Off optical switch, although protection optical fibers are additionally installed therein. The system can rapidly recover fault of optical fibers between a local office and optical network units, 1:N manner, using 2×2 optical switches, which are installed to each of the optical network units, a reserved transmitter and receiver, and a transceiver. The communication recovering system has advantages in that it can simplify network structure, be cost-effectively implemented, reduce optical loss, and rapidly perform protection of optical fiber fault.

A bridgeless power factor correction converter that can reduce common-mode noise and enhance power density is made up of a boost inductor coupled to an input end, a bidirectional switch connected in series with the boost inductor, a first series rectifying circuit having a junction node connected between the boost inductor and the bi-directional switch, a second series rectifying circuit connected in parallel with the first series rectifying circuit and having a junction node coupled to the bi-directional switch, and an output capacitor connected in parallel with the second series rectifying circuit, in which the second series rectifying circuit is made up of slow-recovery diodes and the first series rectifying circuit is made up of fast-recovery diodes.

The increasing number of Internet users and innovative new services such as e-commerce are placing new demands on Web servers. It is becoming essential for Web servers to provide performance isolation, have fast recovery times, and provide continuous service during overload at least to preferred customers. The invention describes a kernel-based architecture for content-aware service differentiation that protects Web servers against overload by controlling the amount and rate of work entering the system. We have invented a mechanism that provides admission control and service differentiation based on connection and application level information. The application header-based connection control uses application-level information (such as URIs and cookies for HTTP) to define different service differentiation actions. The present invention provides the kernel mechanisms that are more efficient and scalable than application level controls implemented in current Web servers.

A technique protects traffic (IP) against the failure of a border router between two domains in a computer network using Fast Reroute and backup tunnels. The border router (i.e., the “protected border router”) announces/advertises a list of all its adjacent next-hop routers (i.e., its “neighbors”) residing in first and second domains interconnected by the protected border router. A neighbor in the first domain that is immediately upstream to the protected border router and that is configured to protect the border router (i.e., the “protecting router”) learns address prefixes (i.e., “protected prefixes”) reachable from the next-hop router in the second domain (i.e., “next-next-hops,” NNHOPs to the protected prefixes from the protecting router). The protecting router calculates a backup tunnel to each NNHOP that excludes the protected border router, and associates each backup tunnel with protected prefixes accordingly. When the protected border router fails, Fast Reroute is triggered, and the protected prefixes are rerouted by the protecting router onto an appropriate backup tunnel to a corresponding NNHOP.

In order to provide a redundancy mechanism in a packet switched provider network, which allows faster recovery from a failure, it is proposed that in case of a failure, a redundancy mechanism is initiated to reroute packet transmission through the provider network via an alternate path and an address withdrawal message is sent to network nodes along the failed path using data plane protocol. A network node receiving the address withdrawal message will flush MAC addresses it had learned before.

The invention provides a distributed back-up mechanism and a two-step method for facilitating fast control plane recovery in a switched network network. In a preferred embodiment, a Label Information Database (LID) maintained at a control node of a GMPLS network is mirrored to an upstream node using the Label Distribution Protocol (LDP). After a control plane interruption resulting in the LDP restart, the control node, using the mirrored information at the upstream node, conducts first a fast coarse LID recovery wherein only the idle labels are identified, to enable the restarted LDP session to process new connection setup. A detailed LDP state information recovery performs in the background in parallel to the normal LDP operations, e.g. using on-demand LDP queries.

A fast recovery extended method is used to enhance the performance of TCP fast recovery when multiple segment losses occur within a single round trip time between a TCP sender and a TCP receiver. A TCP fast recovery process is performed by a TCP sender, and then a TCP fast recovery extended process is performed by the TCP sender upon receiving acknowledgement of receipt of new data from a TCP receiver in the TCP fast recovery process. The fast recovery extended process determines, following receipt of the acknowledgement of receipt of new data, an excess number of duplicate acknowledgements based upon a count of consecutive duplicate acknowledgement packets. The fast recovery extended process takes a network packet transmission recovery action based upon the excess number of duplicate acknowledgements, and then stores the excess number of duplicate acknowledgements as a number of duplicate acknowledgements for further use.

An improved electron multiplier bias network that limits the response of the multiplier when the multiplier is faced with very large input signals, but then permits the multiplier to recover quickly following the large input signal. In one aspect, this invention provides an electron multiplier, having a cathode that emits electrons in response to receiving a particle, wherein the particle is one of a charged particle, a neutral particle, or a photon; an ordered chain of dynodes wherein each dynode receives electrons from a preceding dynode and emits a larger number of electrons to be received by the next dynode in the chain, wherein the first dynode of the ordered chain of dynodes receives electrons emitted by the cathode; an anode that collects the electrons emitted by the last dynode of the ordered chain of dynodes; a biasing system that biases each dynode of the ordered chain of dynodes to a specific potential; a set of charge reservoirs, wherein each charge reservoir of the set of charge reservoirs is connected with one of the dynodes of the ordered chain of dynodes; and an isolating element placed between one of the dynodes and its corresponding charge reservoir, where the isolating element is configured to control the response of the electron multiplier when the multiplier receives a large input signal, so as to permit the multiplier to enter into and exit from saturation in a controlled and rapid manner.

In order to restore a network after a failure, it is important to have sufficient spare capacity available. To ensure restorability, a Hamiltonian mesh, being a closed sequence of links traversing each network node exactly once, is determined and half of its capacity is reserved for restoration purpose. In the case of a line failure of a link other than the links of the Hamiltonian mesh, affected traffic is split in two portions and rerouted over the two directions of the Hamiltonian mesh. In the case the network has no Hamiltonian mesh, a mesh coverage is determined and sufficient spare capacity reserved for restoration purpose.

The teachings presented herein enable a user terminal to perform a fast recovery from a radio link failure. In one aspect, the improvement in recovery time is achieved by commanding or otherwise causing the user terminal to perform radio link failure (RLF) recovery at a cell that is known to possess the user context, while considering that this cell should yield good radio conditions (if not the best) to the user terminal. A cell may be predefined for use by the user terminal in recovering its radio connection. Based on providing signal strength thresholds to the user terminal, for use in determining whether to use a predefined cell for reconnecting to the network, the user terminal attempts RLF recovery first in the predefined cell. By providing user context to the predefined cell in advance of a recovery attempt by the user terminal, the time for recovery is lessened. Note that the user terminal also may infer which cells are preferred.

The present invention relates to protection and restoration method for MPXS in optical mesh networks, particularly to protection and restoration method which can find and restore fast failures by configuring routing table with working label and protection label when failures occur at links or nodes. According to the present invention, by configuring a routing table consisted of working label and protection label and by setting an optical path as working path and protection path, data is transferred through the working path, and when a failure occurs in a optical path, data is transferred through a protection path by using a preliminarily configured protection label and by switching to. According to the present invention, by configuring routing table with working label and protection label, failures can be restored fast when failures occur at links or nodes, and whole network resources can be applicable.

The invention provides a backup method and a backup device for a virtual machine. The method comprises the following steps of: acquiring information of at least one virtual machine on a physical machine; carrying out snapshot treatment on the information of the virtual machine and generating a local snapshot file; and uploading the local snapshot file into a cloud storage server so as to back up the local snapshot file in the cloud storage server. According to the backup method and the backup device for the virtual machine, which are provided by the invention, the information of the virtual machine is subjected to snapshot and the generated local snapshot file is uploaded into the cloud storage server to be backed up, so that the snapshot of the virtual machine cannot occupy a great amount of hard disk resources; and moreover, once a local hard disk goes wrong, the snapshot file of the virtual machine, which is stored in the cloud storage server, cannot be influenced, so that the virtual machine established on the local hard disk can be rapidly recovered and an interrupted service or lost data of a user is reduced.

A system and method is provided for controlling a packet data service in a mobile communication network, in which, when a packet data service active terminal moves from an area of an old radio network controller to an area of a new radio network controller in either a suspended state or a dormant state, the same medium access control state information and the same radio resource control information are applied between the new radio network controller and the active terminal. Therefore, the packet data service can rapidly be resumed on the basis of an initially established point-to-point protocol link. If the active terminal moves from the old radio network controller to the new radio network controller under the condition that only a point-to-point protocol state is maintained between the active terminal and a packet data node, the active terminal detects a received pilot signal and checks a system overhead message. If the active terminal should perform a handoff operation in the suspended state, the active terminal requests the old radio network controller to permit its change to the dormant state or an active state.

This invention broadly comprises a novel segment protection scheme (survivability framework) for a network, which we refer to as PROMISE (Protection using MultIple SEgments). It combines the best of existing link and path protection schemes (e.g., bandwidth efficiency and fast recovery). The PROMISE approach divides an active path or AP (along which a survivable connection is established) into several, possibly overlapping active segments or ASs, and then protects each AS with a detour called backup segment or BS (instead of protecting the AP as a whole as in path protection schemes). This facilitates the bandwidth sharing not only among the BSs for different APs, but also among those for the same AP. In addition, recovery time can be shortened due to the limited length of each AS and BS. This technology can be applied to MPLS, ATM, SONET, WDM and other high-speed link layers under the evolving G-MPLS framework.