This patent document describes failure recovery technologies for the processing of streaming data, also referred to as pipelined data. The technologies described herein have particular applicability in distributed computing systems that are required to process streams of data and provide at-most-once and/or exactly-once service levels. In a preferred embodiment, a system comprises many nodes configured in a network topology, such as a hierarchical tree structure. Data is generated at leaf nodes. Intermediate nodes process the streaming data in a pipelined fashion, sending towards the root aggregated or otherwise combined data from the source data streams towards. To reduce overhead and provide locally handled failure recovery, system nodes transfer data using a protocol that controls which node owns the data for purposes of failure recovery as it moves through the network.

This patent document describes failure recovery technologies for the processing of streaming data, also referred to as pipelined data. The technologies described herein have particular applicability in distributed computing systems that are required to process streams of data and provide at-most-once and/or exactly-once service levels. In a preferred embodiment, a system comprises many nodes configured in a network topology, such as a hierarchical tree structure. Data is generated at leaf nodes. Intermediate nodes process the streaming data in a pipelined fashion, sending towards the root aggregated or otherwise combined data from the source data streams towards. To reduce overhead and provide locally handled failure recovery, system nodes transfer data using a protocol that controls which node owns the data for purposes of failure recovery as it moves through the network.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for storing and transferring messages. An example method includes providing a queue having an ordered plurality of storage blocks. Each storage block stores one or more respective messages and is associated with a respective time. The times increase from a block designating a head of the queue to a block designating a tail of the queue. The method also includes reading, by each of a plurality of first sender processes, messages from one or more blocks in the queue beginning at the head of the queue. The read messages are sent, by each of the plurality of first sender processes, to a respective recipient. One or more of the blocks are designated as old when they have associated times that are earlier than a first time. A block is designated as a new head of the queue when the block is associated with a time later than or equal to the first time. One or more of the first sender processes is allowed to read messages from the old blocks until a second time which is later than the first time. One or more of the old blocks are deleted at a time later than or equal to the second time.

An architecture provides capabilities to transport and process Internet Protocol (IP) packets from Layer 2 through transport protocol layer and may also provide packet inspection through Layer 7. A set of engines may perform pass-through packet classification, policy processing and/or security processing enabling packet streaming through the architecture at nearly the full line rate. A scheduler schedules packets to packet processors for processing. An internal memory or local session database cache stores a session information database for a certain number of active sessions. The session information that is not in the internal memory is stored and retrieved to/from an additional memory. An application running on an initiator or target can in certain instantiations register a region of memory, which is made available to its peer(s) for access directly without substantial host intervention through RDMA data transfer.

A method for accelerating TCP/UDP packet switching. The method involves determining whether exception processing is necessary; if not, the packet is forwarded to a special stack for expedited processing. Packets requiring exception processing are forwarded to the conventional stack.

Disclosed herein is a method including receiving, from a user application, data to be transmitted from a source address to a destination address using a single connection through a network; and splitting the data into a plurality of packets according to a communication protocol. For each packet of the plurality of packets, a respective flowlet for the packet to be transmitted in is determined from a plurality of flowlets; a field in the packet used by a network switch of the network to route the packet is set based on the determined flowlet for the packet; and the packet is sent via the determined flowlet for transmitting through the network.

An architecture provides capabilities to transport and process Internet Protocol (IP) packets from Layer 2 through transport protocol layer and may also provide packet inspection through Layer 7. A set of engines may perform pass-through packet classification, policy processing and/or security processing enabling packet streaming through the architecture at nearly the full line rate. A scheduler schedules packets to packet processors for processing. An internal memory or local session database cache stores a session information database for a certain number of active sessions. The session information that is not in the internal memory is stored and retrieved to/from an additional memory. An application running on an initiator or target can in certain instantiations register a region of memory, which is made available to its peer(s) for access directly without substantial host intervention through RDMA data transfer.

A method for accelerating TCP/UDP packet switching. The method involves determining whether exception processing is necessary; if not, the packet is forwarded to a special stack for expedited processing. Packets requiring exception processing are forwarded to the conventional stack.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for storing and transferring messages. An example method includes providing a queue having an ordered plurality of storage blocks. Each storage block stores one or more respective messages and is associated with a respective time. The times increase from a block designating a head of the queue to a block designating a tail of the queue. The method also includes reading, by each of a plurality of first sender processes, messages from one or more blocks in the queue beginning at the head of the queue. The read messages are sent, by each of the plurality of first sender processes, to a respective recipient. One or more of the blocks are designated as old when they have associated times that are earlier than a first time. A block is designated as a new head of the queue when the block is associated with a time later than or equal to the first time. One or more of the first sender processes is allowed to read messages from the old blocks until a second time which is later than the first time. One or more of the old blocks are deleted at a time later than or equal to the second time.

An exemplary golf club head having an increased amount of discretionary mass may be realized by utilizing improved drop angles, an improved average crown height, and/or articulation points. The discretionary mass may be placed low and deep in the club head to improve the location of the center of gravity as well as the inertial properties. A preferred break length may also be utilized to further improve the depth of the center of gravity. In one example, the center of gravity may be positioned to substantially align the sweet spot with the face center of the club head.