Hewlett-Packard Development Company, L.p.

Alistar Veitch

Arif Abdulhusein Merchant

Svend Frolund

Susan Spence

Yasusuhi Saito

Christos Karamanolis

Mehul A Shah

Marcos Kawazoe Aguilera

Provided is a system and method for directing group communication in a system environment that has a plurality of discrete application nodes networked with at least one discrete memory node, establishing a shared memory providing a passive message queue. A code library permits an application node member of a group to assemble a message selected from the group of send, join, leave, or read. The send, join and leave messages permit a first application node to add a message to the queue for all members of a group including the first application node at the time the message was added. The instruction set permitting the addition of the message is executed atomically.

Group communication system and method

A method of reading data comprises receiving a request for a stripe of erasure coded data, sending read messages to at least a quorum of storage devices, and receiving at least the quorum of reply messages from the devices. The quorum of the reply messages includes at least a minimum number of stripe blocks needed to decode the data. The quorum meets a quorum condition of a number such that any two selections of the number of the stripe blocks intersect in the minimum number of the stripe blocks. A method of writing data comprises generating a timestamp, encoding the data, sending query messages including the timestamp to the storage devices, receiving query reply messages from each of at least the quorum of the devices, sending write messages to the devices, and receiving a write reply message from each of at least the quorum of the devices.

Methods of reading and writing data

A method of reading data comprises sending read messages to storage devices holding the stripe and receiving at least a quorum of reply messages. The reply message from the storage device holding the data block includes the data block. The quorum meets a quorum condition of a number such that any two selections of the number of stripe blocks intersect in the minimum number of the stripe blocks needed to decode the stripe. A method of writing data comprises sending query messages to storage devices holding the stripe, receiving a query reply message from each of at least a first quorum of the storage devices, sending modify messages to the storage devices, and receiving a write reply message from each of at least a second quorum of the storage devices. The first and second quorums each meet the quorum condition.

A method of recovering a stripe of erasure coded data begins with sending query messages to storage devices. The method continues with receiving query reply messages from at least a first quorum of the storage devices. The query reply messages include a minimum number of the stripe blocks needed to decode the stripe. Following this, the stripe of erasure coded data is encoded. Next, a write message is sent to each of the storage devices, which include a timestamp and the stripe block destined for the storage device. The method concludes with receiving a write reply message from at least a second quorum of the storage devices indicating that the stripe block was successfully stored. The first and second quorums each meet a quorum condition of a number such that any two selections of the number of the stripe blocks intersect in the minimum number of the stripe blocks.

Growing community of inventors

Mountain View, CA, United States of America

Alistar Veitch