| Patent application number | Description | Published |
| 20080288646 | DATA CONSISTENCY WITHIN A FEDERATION INFRASTRUCTURE - In some embodiments, it is determined that a primary node has been elected from among a plurality of nodes in a replica set of nodes. The primary node accepts and processes client data access requests. The replica set includes the primary node and other secondary nodes. The primary node receives client data access requests. The primary node assigns a data sequence number to each client data access request that mutates state in the order the client data access requests are received. The data sequence numbers include a linearized processing order that is to be followed by each of the nodes in the replica set. The primary node sends the mutating client data access requests including any corresponding data sequence numbers to the secondary nodes. The primary node receives, from a threshold number of secondary nodes, an acknowledgement indicating reception of the client data access request. The primary node commits the data mutating access request. | 11-20-2008 |
| 20080288659 | MAINTAINING CONSISTENCY WITHIN A FEDERATION INFRASTRUCTURE - The present invention extends to methods, systems, and computer program products for a joining node to join a ring of nodes within a rendezvous federation. Embodiments include detecting a neighborhood of nodes on the ring of nodes. The joining node indicates its intent to take id-space ownership for a portion of the id-space between the joining node and a selected immediately adjacent node. The joining node indicates an intent to monitor the selected node. The joining node receives three indications, the first indicating acceptance of the joining node's intent to take id-space ownership for a portion of the id-space between the joining node and the selected node, the second indicating acceptance of the joining node's intent to monitor the selected node, the third indicating the first selected node's intent to monitor the joining node. The joining node indicates acceptance of the selected node's intent to monitor the joining node. | 11-20-2008 |
| 20090193288 | ROUTING TOKEN TRANSFER AND RECOVERY PROTOCOL IN RENDEZVOUS FEDERATION - Systems and methods that provide for assignment and recovery of tokens as part of a plurality of nodes and distributed application framework/network. The assignment component assigns numbers and tasks to candidates and facilitates multiple leader election. Moreover, a recovery component can recover a token for a node that leaves the network (e.g., crashes). Such recovery component ensures consistency, wherein only one server is assigned recovery of the token and associated tasks. | 07-30-2009 |
| 20090213757 | NEIGHBORHOOD MAINTENANCE IN THE FEDERATION - Systems and methods that provide for joining a node to a federation. A link component facilitates joining such node thru three phases of join, introduce and advise. A plurality of messages and replies are exchanged between nodes in form of introduce, advise, and response messages. Such messages contain the sending node's full neighborhood. | 08-27-2009 |
| 20090319684 | SUBFEDERATION CREATION AND MAINTENANCE IN A FEDERATION INFRASTRUCTURE - A computational system determines that a joining node in the federation infrastructure desires to join an identified subfederation within the federation infrastructure. The system accesses the joining node's group table, where the group table includes membership information identifying subfederations within the federation infrastructure. Each node in the federation maintains neighborhood information for each subfederation of which the node is aware. The system determines that no entry for the identified subfederation exists in the joining node's group table and, based on the determination, routes a group join message to a rendezvous point within the federation infrastructure. The rendezvous point checks its group table for an entry corresponding to the identified subfederation. The system also receives an indication from the rendezvous point indicating that the rendezvous point's group table does not include a corresponding entry for the identified subfederation and that the joining node is the first member of the identified subfederation. | 12-24-2009 |
| 20100106813 | QUORUM BASED TRANSACTIONALLY CONSISTENT MEMBERSHIP MANAGEMENT IN DISTRIBUTED STORAGE SYSTEMS - Systems and methods that restore a failed reconfiguration of nodes in a distributed environment. By analyzing reports from read/write quorums of nodes associated with a configuration, automatic recovery for data partitions can be facilitated. Moreover, a configuration manager component tracks current configurations for replication units and determines whether a reconfiguration is required (e.g., due to node failures, node recovery, replica additions/deletions, replica moves, or replica role changes, and the like.) Reconfigurations of data activated as being replicated from an old configuration to being replicated on a new configuration may be performed in a transactionally consistent manner based on dynamic quorums associated with the new configuration and the old configuration. | 04-29-2010 |
| 20100106831 | BOOTSTRAP RENDEZVOUS FEDERATION - Systems and methods that ensure formation of a single ring from a seed node at any given time. A “bootstrap” phase is included in a node's life cycle, to mitigate adverse affects of split-brain conditions in a network. During such bootstrap phase, if an existing ring is found, the seed node can join the existing ring in a same manner as a non-seed node does. If no ring is detected, the bootstrap phase attempts to elect a seed node to be the “super-seed node”, wherein a new ring can then be formed with such new super-seed node as the first node. | 04-29-2010 |
| 20100107002 | FAILURE NOTIFICATION IN RENDEZVOUS FEDERATION - Systems and methods that supply a global knowledge on what nodes are available in the system, via employing routing tokens that are analyzed by a centralized management component to infer status for the nodes. When nodes fail, the routing tokens associated therewith are acquired by neighboring nodes, and the global knowledge updated. Moreover, upon inferring a failed or down status for a node, a challenge can be sent to a node reporting such failure to verify actual failure(s). | 04-29-2010 |
| 20100114824 | REPLICATION FOR COMMON AVAILABILITY SUBSTRATE - Systems and methods that supply a replication layer/agent that is generic to supporting a plurality of storage configuration as part of a distributed store. Such distributed store employs a Common Availability Substrate (CAS) for data transport and consistency, to render the distributed store scalable and available. Such an arrangement enables continuous operation of the store, while the replication subsystem creates new replicas (e.g., for load balancing, failover, and the like). | 05-06-2010 |
| 20100114826 | CONFIGURATION MANAGEMENT IN DISTRIBUTED DATA SYSTEMS - Systems and methods for managing configurations of data nodes in a distributed environment A configuration manager is implemented as a set of distributed master nodes that may use quorum-based processing to enable reliable identification of master nodes storing current configuration information, even if some of the master nodes fail. If a quorum of master nodes cannot be achieved or some other event occurs that precludes identification of current configuration information, the configuration manager may be rebuilt by analyzing reports from read/write quorums of nodes associated with a configuration, allowing automatic recovery of data partitions. | 05-06-2010 |
| 20100293334 | LOCATION UPDATES FOR A DISTRIBUTED DATA STORE - Version indicators within an existing range can be associated with a data partition in a distributed data store. A partition reconfiguration can be associated with one of multiple partitions in the data store, and a new version indicator that is outside the existing range can be assigned to the reconfigured partition. Additionally, a broadcast message can be sent to multiple nodes, which can include storage nodes and/or client nodes that are configured to communicate with storage nodes to access data in a distributed data store. The broadcast message can include updated location information for data in the data store. In addition, a response message can be sent to a requesting node of the multiple nodes in response to receiving from that node a message that requests updated location information for the data. The response message can include the requested updated location information. | 11-18-2010 |
| 20100318584 | Distributed Cache Availability During Garbage Collection - Techniques are described herein for managing access to a distributed cache during garbage collection. When garbage collection is to be performed with respect to a node, the node may send a request to a data manager requesting to have an instance of data module(s) included in the node that are in a primary state placed in a secondary state. The data manager may change the state of the data module(s) to the secondary state. The data manager may change the state of another instance of the data module(s) that is included in another node to the primary state. When the garbage collection is complete with respect to the node, the node may send another request to the data manager requesting that the data module(s) that were placed in the secondary state be returned to the primary state. The data manager may return those data module(s) to the primary state. | 12-16-2010 |
| 20110016090 | Hierarchical Scale Unit Values for Storing Instances of Data Among Nodes of a Distributed Store - Techniques are described herein for storing instances of data among nodes of a distributed store based on hierarchical scale unit values. Hierarchical scale unit values are assigned to the respective nodes of the distributed store. A first instance (e.g., a primary instance) of a data module is stored in a first node having a first hierarchical scale unit value. A primary instance of the data module with respect to a data operation is an instance of the data module at which the data operation with respect to the data module is initiated or initially directed. A second instance (e.g., a primary or secondary instance) of the data module is stored in a second node having a second hierarchical scale unit value based on a magnitude of a difference between the first hierarchical scale unit value and the second hierarchical scale unit value. A secondary instance is essentially a “back-up” instance. | 01-20-2011 |
| 20110082928 | MAINTAINING CONSISTENCY WITHIN A FEDERATION INFRASTRUCTURE - The present invention extends to methods, systems, and computer program products for a joining node to join a ring of nodes within a rendezvous federation. Embodiments of the invention include establishing a neighborhood of multiple nodes on the ring of nodes. The joining node indicates its intent to take id-space ownership for a portion of the id-space between the joining node and a selected immediately adjacent node. The joining node initiates a one-way monitoring relationship with the selected immediately adjacent node. The joining node receiving an indication from the selected immediately adjacent node that indicates acceptance of the joining node's intent to take id-space ownership for a portion of the id-space between the joining node and the selected node and indicates establishment of a one-way monitoring relationship between the selected node and the joining node. The joining node agrees to participate in a one-way monitoring relationship with the selected node. | 04-07-2011 |