Open Invention Network LLC

Librato, Inc.

International Business Machines Corporation

Virginia Tech Intellectual Properties, Inc.

Joseph F Ruscio

Srinidhi Varadarajan

Michael Heffner

Log-Based Rollback Recovery for system failures. The system includes a storage medium, and a component configured to transition through a series of states. The component is further configured to record in the storage medium the state of the component every time the component communicates with another component in the system, the system being configured to recover the most recent state recorded in the storage medium following a failure of the component.

Log-based rollback-recovery

A distributed system for creating a checkpoint for a plurality of processes running on the distributed system. The distributed system includes a plurality of compute nodes with an operating system executing on each compute node. A checkpoint library resides at the user level on each of the compute nodes, and the checkpoint library is transparent to the operating system residing on the same compute node and to the other compute nodes. Each checkpoint library uses a windowed messaging logging protocol for checkpointing of the distributed system. Processes participating in a distributed computation on the distributed system may be migrated from one compute node to another compute node in the distributed system by re-mapping of hardware addresses using the checkpoint library.

Transparent checkpointing and process migration in a distributed system

Approaches to efficiently creating a checkpoint of the process are described. In one approach, a method of performing a checkpoint operation on a process involves detecting a change in the contents of a memory page associated with the process. This change occurred after a preceding checkpoint operation. The method also involves modifying a data structure, at a location corresponding to the contents of that memory page.

Efficient checkpoint process

Concurrent checkpointing for rollback recovery for system failures is disclosed. The system includes a stable database, and a processor configured to receive and process a checkpoint request while a first thread performs a process and a second thread stores contents of memory regions listed in a first list to the stable storage. Processing the checkpoint request includes write protecting all memory regions listed in a previously initialized and populated second list, initializing an empty third list, creating a coalesced list by combining the contents of the first and second lists, and assigning the coalesced list to the second thread while the first thread proceeds with the process.

Method for checkpointing a system already engaged in a concurrent checkpoint

A method of identifying the source of a memory corruption error during operation of a checkpoint library includes receiving an error detection request and, in response to the request, write protecting all memory regions allocated to a checkpoint library. The method further includes detecting when a memory region is accessed for modification during operation of the checkpoint library and, in response to the detection, identifying the source of a memory corruption error affecting the memory region.

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Blacksburg, VA, United States of America

Joseph F Ruscio