Symantec Operating Corporation

Symantec Corporation

Amdahl Corporation

Akamai Technologies, Inc.

Cypress Semiconductor Corporation

Kai Chiu Wong

Harold B Prince, Jr

Dan F Greiner

Gregory L Slaughter

Anindya Banerjee

Philip A Lisiecki

John A Muth

Navin Kabra

Balemurughan Kumaresan

Bala Kumaresan

Andrew K Krumel

Ruchir Tewari

Sivaramakrishna Ramadugu Venkata

Bijaya Laxmi Nanda

Mark vonGnechten

Paul Czarnik

John Turnbull Cattanach

Sung Chiu

Ronald K Kreuzenztein

A data storage system with quorum-based commits sometimes experiences replica failure, due to unavailability of a replica-hosting node, for example. Described herein are methods and systems for improving data persistence and availability in a distributed data store where data is stored in a plurality of shards and a given shard is replicated across a plurality of nodes so as to create a plurality of replicas, and a quorum of replicas is needed for access to the given shard. Among other things, the methods and systems generally involve determining whether to quarantine or delete unavailable replicas in a given shard, and how to handle purge requests related to the shard when there are quarantined replicas.

Quarantine and repair of replicas in a quorum-based data storage system

In a distributed computing system, the allocation of workers to tasks can be challenging. In embodiments described herein, nodes in such a system can execute takeover algorithms that provide efficient, automated, and stable allocation of workers to tasks.

Systems and methods for allocating work for various types of services among nodes in a distributed computing system

Systems and methods for process flow tracking are presented. In one embodiment, a flow method comprises collecting records associated with flow for post analysis; performing a flow connection process associated with the flow, wherein the flow connection process examines information in a hash table and connects flow segments based upon connect ID; and performing a presentation process in which the flow is visualized, searched and traversed. In one exemplary implementation, a flow connection process utilizes a hash table that draws a correlation between the connect ID and a connect-start record or a connect-end record.

Flow systems and methods

A method, system, computer-readable storage medium and apparatus for balanced and consistent placement of resource management responsibilities within a multi-computer environment, such as a cluster, that are both scalable and make efficient use of cluster resources are provided. Embodiments reduce the time that a cluster is unavailable due to redistribution of resource management responsibilities by reducing the amount of redistribution of those responsibilities among the surviving cluster members. Embodiments further provide redistribution of resource management responsibilities based upon relative capabilities of the remaining cluster nodes.

Balanced consistent hashing for distributed resource management

A system and method related for performing lookup operations for objects distributed among different nodes in a peer-to-peer network are disclosed. Various nodes in the peer-to-peer network may store objects. Objects stored on a given node may be accessed by other nodes in the peer-to-peer network. To access an object, a node may first perform a lookup operation to determine where the object is stored, i.e., to determine which node in the peer-to-peer network stores the object. The peer-to-peer network may utilize a method to improve the performance of object lookup operations. In one embodiment, the method may allow object lookup operations to be performed with a latency on the order of one hop.

Fast distributed object lookup for a computer network

In one embodiment, a virtual NUMA machine is formed from multiple computers coupled to a network. Each computer includes a memory and a hardware device coupled to the memory. The hardware device is configured to communicate on the network, and more particularly is configured to perform remote direct memory access (RDMA) communications on the network to access the memory in other computers. A guest physical address space of the virtual NUMA machine spans a portion of the memories in each of the computers, and each computer serves as a home node for at least one respective portion of the guest physical address space. A software module on a first computer uses RDMA to coherently access data on a home node of the data without interrupting execution in the home node.

Efficient data transfer between computers in a virtual NUMA system using RDMA

In one embodiment, a virtual NUMA system may be formed from multiple computer systems coupled to a network such as InfiniBand, Ethernet, etc. Each computer includes one or more software modules which present the resources of the computers as a virtual NUMA machine. The virtual machine is a non-uniform memory access (NUMA) machine comprising a plurality of nodes, each node having memory that is part of a distributed shared memory. Additionally, the virtual machine is coherent with a weakly ordered memory model. When executed in a current owner node of a first block in response to an ownership transfer request from a requesting node of the plurality of nodes for the first block, the software modules perform a synchronization operation if the first block has been modified in the current owner node.

Supporting a weak ordering memory model for a virtual physical address space that spans multiple nodes

A method and system for implementing a global name space service. The method may include receiving a file system unique identifier corresponding to a particular file and a human-readable name corresponding to the same file. The method may further include binding the human-readable name to the file system unique identifier, thereby creating a mapping between the human-readable name and the file system unique identifier. The system may include a processor coupled to a memory and to a global name space service manager. The global name space service manager may be configured to receive a file system unique identifier corresponding to a particular file and a human-readable name corresponding to the same file. The global name space service manager may be further configured to bind the human-readable name to the file system unique identifier, thereby creating a mapping between the human-readable name and the file system unique identifier.

Method and system for implementing a global name space service

In one embodiment, a virtual NUMA system may be formed from multiple computer systems coupled to a network such as InfiniBand, Ethernet, etc. Each computer includes one or more software modules which present the resources of the computers as a virtual NUMA machine. A single instance of a guest operating system executes on the virtual NUMA machine. The guest operating system is designed to execute on a NUMA system and executes without modification on the virtual machine. The memory model of the virtual NUMA machine includes a single writer, multiple reader memory model.

Virtual machine spanning multiple computers

An efficient distributed transaction protocol for a distributed file sharing system is described. One embodiment of the protocol involves a transaction coordinator node sending three messages to participant nodes, where the participant nodes reply to only two of those messages. In one embodiment, the transaction coordinator node may return success to the client application after receiving replies to the second message from the participant nodes. The protocol may provide benefits associated with traditional three-phase commit (3PC) protocols while also decreasing response time latencies experienced by client applications and decreasing network traffic.

Efficient distributed transaction protocol for a distributed file sharing system

The present invention is a mask ordering method and apparatus which controls the way keys are compared. In its general form, the mask ordering method operates to order (with a less than, greater than or equal to comparison) two N-byte (for example, N&equals;16) keys (Key and Key ) using an N-bit ordering mask where the N bits in the ordering mask correspond one for one with the N bytes in the keys in the same compare direction (either left-to-right or right-to-left).

Ordering keys in a table using an ordering mask

A system that employs virtual addressing for structures in a coupling facility. The system operates to share data among two or more processes that execute on central processing complexes. The central processing complexes each have an inter-system channel connected to a coupling facility. The coupling facilitcludes coupling facility receivers where each receiver connects to one of the inter-system channels for making transfers between the coupling facility and the central processing complexes. The coupling facility includes storage, connected to the coupling facility receivers, for storing control objects and data objects at real addresses in one or more structures, where the real address are translatable from corresponding virtual addresses. The coupling facility includes CPUs, connected to the coupling facility receivers and to the storage, for controlling the operation of the coupling facility. Each of the CPUs includes a dynamic address translator for translating the virtual addresses to the real addresses.

Coupling facility using dynamic address translation

The invention enables extension of the useful life of a chemical bath used to process a substrate. The invention can employ an improved rinsing method that removes defects from a substrate with sufficient effectiveness to obtain acceptable defect levels even as the quality (e.g., composition and/or contaminant level) of the chemical bath degrades over time such that substrates that are immersed in the bath accumulate more defects than can be adequately removed by previous rinsing methods. For example, the invention can enable a stagnant chemical bath to be used for a period greater than 24 hours without replacing the bath fluid. Similarly, it is expected that use of the invention can enable a recirculated chemical bath to be used for a period greater than 48 hours without replacing the bath fluid. In particular, the invention can advantageously enable a chemical bath to be used continuously for such extended periods of time, thus reducing the costs associated with stopping use of a chemical bath (to replace the bath fluid or for any other reason). The invention can be used with chemical baths of any of a variety of fluids, including both liquid and gas baths. For example, the invention can be used with a chemical bath that includes (or consists essentially of) sulfuric peroxide, a chemical bath that includes (or consists essentially of) phosphoric acid, or a chemical bath that includes (or consists essentially of) a metal stripping solvent.

Extension of the useful life of a chemical bath used to process a substrate

A SYStem COMmunication interface (SYSCOM) unit provides uniform communication between hardware and software units of a computer system. The computer units include Central Processing Units (CPU's), Input/Output Processors (IOP's), Service Processor (SVP), and Control State Software (CSSW) which runs on the CPU's operating in Control State. The SYSCOM communication interface includes signalling hardware, control blocks in storage, and a uniform communication method used for communication between the computer units. The communication method sends messages between an originating unit (ORG.U) and one or more destination unit(s) [DES.U(s)].

Growing community of inventors

Saratoga, CA, United States of America

Kai Chiu Wong