Abstract: Data stored within a cluster may be distributed among nodes each storing a portion of the data. The data may be replicated wherein different nodes store copies of the same portion of the data. In response to detecting the failure of a node, the cluster may initiate a timeout period. If the node remains failed throughout the timeout period, the cluster may copy the portion of the data stored on the failed node onto one or more other nodes of the cluster. If the node returns to the cluster during the timeout period, the cluster may maintain the copy of the data on the previously failed node without copying the portion of the data stored on the failed node onto any other nodes. By delaying self-healing of the cluster for the timeout period, an unbalanced data distribution may be avoided in cases where a failed node quickly rejoins the cluster.

Abstract: A distributed system provides for separate management of dynamic cluster membership and distributed data. Nodes of the distributed system may include a state manager and a topology manager. A state manager handles data access from the cluster. A topology manager handles changes to the dynamic cluster topology. The topology manager enables operation of the state manager by handling topology changes, such as new nodes to join the cluster and node members to exit the cluster. A topology manager may follow a static topology description when handling cluster topology changes. Data replication and recovery functions may be implemented, for example to provide high availability.

Abstract: A distributed system provides for separate management of dynamic cluster membership and distributed data. Nodes of the distributed system may include a state manager and a topology manager. A state manager handles data access from the cluster. A topology manager handles changes to the dynamic cluster topology. The topology manager enables operation of the state manager by handling topology changes, such as new nodes to join the cluster and node members to exit the cluster. A topology manager may follow a static topology description when handling cluster topology changes. Data replication and recovery functions may be implemented, for example to provide high availability.

Abstract: A distributed system provides for separate management of dynamic cluster membership and distributed data. Nodes of the distributed system may include a state manager and a topology manager. A state manager handles data access from the cluster. A topology manager handles changes to the dynamic cluster topology. The topology manager enables operation of the state manager by handling topology changes, such as new nodes to join the cluster and node members to exit the cluster. A topology manager may follow a static topology description when handling cluster topology changes. Data replication and recovery functions may be implemented, for example to provide high availability.

Abstract: A system and method for enabling failover in an application server cluster. A “primary” application server computer in the cluster may provide a service or data necessary for other application server computers in the cluster to operate. In addition to the primary application server computer, one or more of the other application server computers may be designated as “backup” application server computers. Each backup application server may backup the processing information managed by the primary application server. When the primary application server itself becomes unavailable (e.g., due to a failure of the computer system or network), one or more of the backup application servers may be promoted to the role of primary application server.

Abstract: A distributed system may include different nodes having different distributed data management configurations in the same distributed data system. A node may include a distributed data manager in a process space for handling requests for data storage and retrieval from clients to the distributed data system. A client may share the same process space in some nodes and may have a distinct process space from a distributed data manager in other nodes. The distributed data system enables the transmission of serialized data among nodes. Nodes in the same distributed data system may store distributed data in serialized or deserialized format depending on their configuration. Various functionalities, such as load balancing or high availability may be implemented using the distributed data system.

Abstract: A system and method for controlling access to data in a distributed computer system. Distributed Token Manager (DTM) is a system-level service that coordinates read/write access of data objects (tokens) in a multi-process and multi-threaded environment. The DTM ensures that at any given time either: 1) One or more client processes or threads currently have read access rights to the data object, and no client processes or threads currently have write access rights to the data object; or 2) One client process or thread currently has write access to the data object and no other client processes or threads currently have read or write access rights to the data object. DTM also ensures that such coordination works smoothly even in the case of process/machine/network failure.