Abstract: A method includes receiving a request via a peer-to-peer network at a first media device from a second media device. The request indicates a portion of video content and also indicates a time that delivery of the portion of video content to the second media device is to be completed. The method further includes transmitting, based on a data rate, the portion from the first media device to the second media device. The data rate is based on a bandwidth that is less than an available bandwidth usable by the first media device to transmit data and that is greater than or equal to a bandwidth threshold for serving the request. The bandwidth threshold is based on the time indicated by the request.

Abstract: A plurality of portions of a video content item is distributed to a plurality of peers, respectively, of a peer-to-peer network. Each of the plurality of portions encodes less than an entire portion of the video content item. A peer of the network retrieves at least a subset of the plurality of portions of the video content item from at least a subset of the peers. The at least the subset of the plurality of portions of the video content item enables recovery of the video content item by the peer.

Abstract: In an Internet Protocol Television (IPTV) system, an IPTV server is configured to receive a request from an IPTV content storage device (CSD) to view a video stream. The IPTV server selects a set of peers for the IPTV CSD, and transmits the set of peers to the IPTV CSD. In the system, a capacity of a fiber to the node (FTTN) switch in a down linking direction is greater than or equal to a sum of a number of simultaneous viewers supported by the FTTN switch plus a number of viewers that receive video streams from peers in the same community.

Abstract: Channels between routers for use in packet routing via payload inspection. The channels constitute logical connections between routers and include subjects and attributes. Publishers create channels for routing particular types of content as defined by the subjects and attributes. The publishers also create proxies and notifications on the channels. The channel definitions for routers identify packet or message structures so that the routers can locate attributes in the packets for content-based routing. The routers apply the packet attributes to filters encapsulating subscriptions in order to perform the content-based routing in the network core. The routers also locally cache content, providing distributed caching of content throughout the network core.

Abstract: Packet routing via payload inspection at routers in a core of a distributed network for use in distributing content according to quality of service guarantees. Packets contain subjects and attributes in addition to routing information. The subjects correspond with particular types of content for subscriptions, and the attributes encapsulate the data or content. The subscriptions are associated with particular quality of service guarantees or levels of service. The routers store filters corresponding with subscriptions to content. Upon receiving a packet, a router inspects the payload section of the packet containing the attributes in order to retrieve the attributes and match them to the filters for the subscriptions. If the attributes satisfies a filter, the packet is routed to the next link in accordance with the quality of service guarantee associated with that filter. If the attributes do not satisfy any of the filters injected to and stored at the router, the router discards the packet.

Abstract: Channels between routers for use in packet routing via payload inspection. The channels constitute logical connections between routers and include subjects and attributes. Publishers create channels for routing particular types of content as defined by the subjects and attributes. The publishers also create proxies and notifications on the channels. The channel definitions for routers identify packet or message structures so that the routers can locate attributes in the packets for content-based routing. The routers apply the packet attributes to filters encapsulating subscriptions in order to perform the content-based routing in the network core. The routers also locally cache content, providing distributed caching of content throughout the network core.

Abstract: A plurality of portions of a video content item is distributed to a plurality of peers, respectively, of a peer-to-peer network. Each of the plurality of portions encodes less than an entire portion of the video content item. A peer of the network retrieves at least a subset of the plurality of portions of the video content item from at least a subset of the peers. The at least the subset of the plurality of portions of the video content item enables recovery of the video content item by the peer.

Abstract: In an Internet Protocol Television (IPTV) system, an IPTV server is configured to receive a request from an IPTV content storage device (CSD) to view a video stream. The IPTV server selects a set of peers for the IPTV CSD, and transmits the set of peers to the IPTV CSD. In the system, a capacity of a fiber to the node (FTTN) switch in a down linking direction is greater than or equal to a sum of a number of simultaneous viewers supported by the FTTN switch plus a number of viewers that receive video streams from peers in the same community.

Abstract: A method and apparatus provide for persistent caching of methods delivered via a publish-subscribe network. At a first node, a message having data via the network is received. The data is time-marked. The data is cached in a cache memory at the first node. The message is routed to a second node using content-based routing. These steps are repeated at a second node. A router that includes modules for executing this method is provided. A publish-subscribe network that includes nodes that include modules for executing this method is provided. A computer-readable medium that includes instructions for executing this method is provided.

Abstract: A distributed computing system includes a number of computers, workstations or other computing machines interconnected by a network. One or more service managers are introduced that provide a management interface to corresponding middleware services. The service manager monitors the corresponding middleware service, as well as the underlying distributed computer environment on which an application process that utilizes the middleware service is executing, and allows the middleware service to operate more efficiently, in response to run-time environmental conditions. A fault-tolerance service manager is provided as a management interface to a fault-tolerance service. The fault-tolerance service manager monitors the fault-tolerance service, as well as the underlying distributed computer environment, to make globally optimal decisions, based on run-time environmental data, and to provide the resulting information to the fault-tolerance service.

Abstract: Packet routing via payload inspection at routers in a core of a distributed network for use in distributing digital content such as video, music, and software. Packets include subjects and attributes in addition to routing information. The subjects correspond with particular types of content for subscriptions, and the attributes encapsulate the data or content, which can include video, music, or software such as software updates. The routers store filters corresponding with subscriptions to content. Upon receiving a packet, a router inspects the payload section of the packet containing the attributes in order to retrieve the attributes and apply them to the filters for the subscriptions to the digital content. If an attribute satisfies a filter, the packet is routed to the next link. If the attributes do not satisfy the filters, the router discards the packet. These routing decisions are distributed among routers in the network core.

Abstract: Packet routing via payload inspection at routers in a core of a distributed network for use in distributing content according to quality of service guarantees. Packets contain subjects and attributes in addition to routing information. The subjects correspond with particular types of content for subscriptions, and the attributes encapsulate the data or content. The subscriptions are associated with particular quality of service guarantees or levels of service. The routers store filters corresponding with subscriptions to content. Upon receiving a packet, a router inspects the payload section of the packet containing the attributes in order to retrieve the attributes and match them to the filters for the subscriptions. If the attributes satisfies a filter, the packet is routed to the next link in accordance with the quality of service guarantee associated with that filter. If the attributes do not satisfy any of the filters injected to and stored at the router, the router discards the packet.

Abstract: A method and apparatus provide for persistent caching of methods delivered via a publish-subscribe network. At a first node, a message having data via the network is received. The data is time-marked. The data is cached in a cache memory at the first node. The message is routed to a second node using content-based routing. These steps are repeated at a second node. A router that includes modules for executing this method is provided. A publish-subscribe network that includes nodes that include modules for executing this method is provided. A computer-readable medium that includes instructions for executing this method is provided.

Abstract: Channels between routers for use in packet routing via payload inspection. The channels constitute logical connections between routers and include subjects and attributes. Publishers create channels for routing particular types of content as defined by the subjects and attributes. The publishers also create proxies and notifications on the channels. The channel definitions for routers identify packet or message structures so that the routers can locate attributes in the packets for content-based routing. The routers apply the packet attributes to filters encapsulating subscriptions in order to perform the content-based routing in the network core. The routers also locally cache content, providing distributed caching of content throughout the network core.

Abstract: Methods and apparatus for hosting a network service on a cluster of servers, each including a primary and a secondary Internet Protocol (IP) address. A common cluster address is assigned as the secondary address to each of the servers in the cluster. The cluster address may be assigned in UNIX-based servers using an ifconfig alias option, and may be a ghost IP address that is not used as a primary address by any server in the cluster. Client requests directed to the cluster address are dispatched such that only one of the servers of the cluster responds to a given client request. The dispatching may use a routing-based technique, in which all client requests directed to the cluster address are routed to a dispatcher connected to the local network of the server cluster. The dispatcher then applies a hash function to the client IP address in order to select one of the servers to process the request.

Abstract: An application module (A) running on a host computer in a computer network is failure-protected with one or more backup copies that are operative on other host computers in the network. In order to effect fault protection, the application module registers itself with a ReplicaManager daemon process (112) by sending a registration message, which message, in addition to identifying the registering application module and the host computer on which it is running, includes the particular replication strategy (cold backup, warm backup, or hot backup) and the degree of replication associated with that application module. The backup copies are then maintained in a fail-over state according to the registered replication strategy. A WatchDog daemon (113), running on the same host computer as the registered application periodically monitors the registered application to detect failures.

Abstract: An application module (A) running on a host computer in a computer network is failure-protected with one or more backup copies that are operative on other host computers in the network. In order to effect fault protection, the application module registers itself with a ReplicaManager daemon process (112) by sending a registration message, which message, in addition to identifying the registering application module and the host computer on which it is running, includes the particular replication strategy (cold backup, warm backup, or hot backup) and the degree of replication associated with that application module. The backup copies are then maintained in a fail-over state according to the registered replication strategy. A WatchDog daemon (113), running on the same host computer as the registered application periodically monitors the registered application to detect failures.

Abstract: A distributed computing system includes a number of computers, workstations or other computing machines interconnected by a network. A non-interactive process arriving in a host machine of the system is migrated for execution to at least two remote machines. For example, first and second executions of the process may be started on respective first and second remote machines. One of the first and second executions of the process is then used to provide an on-demand checkpoint for the other execution of the process in the event the other execution is terminated, such that an additional execution of the process can be started from the on-demand checkpoint. This on-demand checkpointing is augmented with periodic checkpointing performed on at least one of the multiple executions of the process.

Abstract: By checkpointing and restoring a user application process, that includes a volatile state and a persistent state, recovery of an application process from the checkpoint position is possible. Specifically, a volatile state is checkpointed in a checkpoint position. Next, the persistent state is monitored to detect a file operation following a checkpoint position that will modify the persistent state. Then, portions of the persistent state are checkpointed if a modification of the persistent state is about to be performed. Then, a recovery to the checkpoint position can be performed such that modifications to the persistent state since the checkpoint position are undone. This allows for resumption of the user application process from the checkpoint position.

Abstract: A checkpoint and restoration system is disclosed to provide checkpoint and restoration techniques for user application processes which save the process state, including the volatile state and desired portions of the persistent state, during normal execution, and thereafter restore the saved state. A lazy checkpoint technique is disclosed which delays the taking of the persistent state checkpoint until an inconsistency between the checkpointed volatile state and a portion of the persistent state is about to occur. The disclosed checkpoint and restoration system allows a user or a user application process to specify selected portions of the persistent state to be excluded from a checkpoint. A selected portion of the pre-restoring process state, such as a return value argument, may be protected before restoring the user application process to a checkpointed state, so that the pre-restoration values of the protected state are retained following restoration of the checkpoint.