Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: The present invention extends to methods, systems, and computer program products for appropriately detecting node failures in a rendezvous federation. A monitor node monitors a subject node. The subject node intermittently renews a time-to-live duration value with the monitor node to indicate the monitor node that the subject node has not failed. In some embodiments, each node in a pair of nodes monitors the other nodes in the pair of nodes. Thus, each node is a subject node and a monitor node. In further embodiments, an arbitration facility arbitrates failure reports.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention extends to methods, systems, and computer program products for allocating and reclaiming resources within a rendezvous federation. Embodiments of the invention include formulating and routing messages in accordance with cached two-way agreements between adjacent nodes on a ring of nodes. Cached two-way agreements divide responsibility for at least unoccupied identifiers between the adjacent nodes on a ring. When a message is received at a node, the node can refer to a cached two-way agreement to determine if it or an adjacent node is responsible for the message. The node then sends the message to the next appropriate component in accordance with the cached two-way agreement.

Abstract: The present invention extends to methods, systems, and computer program products for appropriately detecting node failures in a rendezvous federation. A monitor node monitors a subject node. The subject node intermittently renews a time-to-live duration value with the monitor node to indicate the monitor node that the subject node has not failed. In some embodiments, each node in a pair of nodes monitors the other nodes in the pair of nodes. Thus, each node is a subject node and a monitor node. In further embodiments, an arbitration facility arbitrates failure reports.

Abstract: The present invention extends to methods, systems, and computer program products for broadcasting communication within a rendezvous federation. Embodiments of the invention include inter-ring and intra-ring communication. Inter-ring communication includes sending a message to destination rings included in a node's Collateral Ring Set entry table. When a node identifies a destination ring that has not yet received a message, the node can send a ring notification message. The ring notification message propagates towards a publishing node until a responsible node in the message path to the publishing node is identified. The responsible node updates its entry table to include the ring and forwards the message to the destination ring. Intra-ring communication can include recursively partitioning ranges of nodes within a ring and forwarding the message to nodes included the partitioned ranges.

Abstract: The present invention extends to methods, systems, and computer program products for facilitating inter-proximity communication within a rendezvous federation. Nodes maintain collateral ring set entry tables that include collateral rings and corresponding entry nodes into the collateral rings. Nodes can exchange collateral ring set entry state to update one another on the configuration of rings within a tree of rings. Nodes can refer to collateral ring set entry tables, as well as to other nodes, to identify entry nodes into rings that are collateral rings of the node. Messages can be sent to entry nodes in collateral rings. A message can include an indication that an entry node in a target proximity ring is to resolve the message to the node in the target proximity ring which has a node ID closest to an indicated destination node.

Abstract: The present invention extends to methods, systems, and computer program products for facilitating inter-proximity communication within a rendezvous federation. Nodes maintain collateral ring set entry tables that include collateral rings and corresponding entry nodes into the collateral rings. Nodes can exchange collateral ring set entry state to update one another on the configuration of rings within a tree of rings. Nodes can refer to collateral ring set entry tables, as well as to other nodes, to identify entry nodes into rings that are collateral rings of the node. Messages can be sent to entry nodes in collateral rings. A message can include an indication that an entry node in a target proximity ring is to resolve the message to the node in the target proximity ring which has a node ID closest to an indicated destination node.