Abstract: Nested recovery scope management systems and methods for a multiple process computer system having a dynamic multiple address space server are disclosed. Stateless recovery agents are employed, under the control of a supervisory program called Recovery Director, during initialization or restart of servers to restore recoverable data in response to identified failures or other abnormal termination. The Director controls the recovery of protected resources in a systematic manner. The Director is initialized when a first address space of a first server is started. Then, as each instance of a recoverable component is initialized, the component registers with the Director by providing a reference to a stateless recovery agent that can later perform recovery functions for it if needed. As part of the registration, a token representing the current failure scope of the registration is generated and provided to the recoverable component by the Director.

Abstract: A histogram, or resource status history table, for multiple resources is created and maintained. A transaction or resource manager arranges and/or reorders various resources into a sequence based on the histogram such that read-only resources are prepared first and a sole non-read-only resource need not be prepared, but only committed. The transaction manager heuristically determines the order that resources are driven to achieve last-agent optimization. The histogram is kept related to context, based on runtime and applications context to ensure that usage patterns by context are optimized without the need for the installation to know any usage patterns.

Abstract: Resources used by components are aggressively reclaimed, in order to enable those resources to be available to other components. To aggressively reclaim one or more resources of a component, the component is forced to transition from one state to a reclaim state, and at the reclaim state, the resources are reclaimed, if necessary.

Abstract: Nested recovery scope management systems and methods for a multiple process computer system having a dynamic multiple address space server are disclosed. Stateless recovery agents are employed, under the control of a supervisory program called Recovery Director, during initialization or restart of servers to restore recoverable data in response to identified failures or other abnormal termination. The Director controls the recovery of protected resources in a systematic manner. The Director is initialized when a first address space of a first server is started. Then, as each instance of a recoverable component is initialized, the component registers with the Director by providing a reference to a stateless recovery agent that can later perform recovery functions for it if needed. As part of the registration, a token representing the current failure scope of the registration is generated and provided to the recoverable component by the Director.

Abstract: An exemplary embodiment of the invention is a method for providing a path-sensitive branch registry for cyclic distributed transactions. This method requires that a superior node's transaction manager (TM) identify itself as the root followed by sending the syncpoint cue to at least one subordinate node. Before sending the syncpoint cues to the subordinate the superior links the inbound messages with its specific branch qualifier (BQUAL) as well as a global transaction identifier (GTRID). The TM of each subordinate node receives syncpoint cues and is responsible for knowing who its superior is. In addition, the TM is responsible for recognizing the flow of branch instructions and guarantee that it uses a network-wide unique value for the branch values it generates for a given global transaction. With the recognition of the flow from the superior node the subordinate TM updates the node registry as to the inbound and outbound flow of branch messages by its superior and its subordinates.

Abstract: Nested recovery scope management systems and methods for a multiple process computer system having a dynamic multiple address space server are disclosed. Stateless recovery agents are employed, under the control of a supervisory program called Recovery Director, during initialization or restart of servers to restore recoverable data in response to identified failures or other abnormal termination. The Director controls the recovery of protected resources in a systematic manner. The Director is initialized when a first address space of a first server is started. Then, as each instance of a recoverable component is initialized, the component registers with the Director by providing a reference to a stateless recovery agent that can later perform recovery functions for it if needed. As part of the registration, a token representing the current failure scope of the registration is generated and provided to there coverable component by the Director.

Abstract: Resources used by components are aggressively reclaimed, in order to enable those resources to be available to other components. To aggressively reclaim one or more resources of a component, the component is forced to transition from one state to a reclaim state, and at the reclaim state, the resources are reclaimed, if necessary.

Abstract: An exemplary embodiment of the invention is a method for providing a path-sensitive branch registry for cyclic distributed transactions. This method requires that a superior node's transaction manager (TM) identify itself as the root followed by sending the syncpoint cue to at least one subordinate node. Before sending the syncpoint cues to the subordinate the superior links the inbound messages with its specific branch qualifier (BQUAL) as well as a global transaction identifier (GTRID). The TM of each subordinate node receives syncpoint cues and is responsible for knowing who its superior is. In addition, the TM is responsible for recognizing the flow of branch instructions and guarantee that it uses a network-wide unique value for the branch values it generates for a given global transaction. With the recognition of the flow from the superior node the subordinate TM updates the node registry as to the inbound and outbound flow of branch messages by its superior and its subordinates.