Abstract: A system and method for managing shared resources is disclosed. The system includes a primary coherency processing unit which processes lock requests from a plurality of data processing hosts, the primary coherency processing unit also storing a first current lock state information for the plurality of data processing hosts, the first current lock state information including a plurality of locks held by the plurality of data processing hosts. The system further includes a standby coherency processing unit storing fewer locks than the primary coherency processing unit, the locks stored by the standby coherency processing unit being a subset of locks included in the first current lock state information, the standby coherency unit configured to perform a plurality of activities of the primary coherency processing unit using the subset of locks in response to a failure of the primary coherency processing unit.

Abstract: A system and method for managing shared resources is disclosed. The system includes a primary coherency processing unit which processes lock requests from a plurality of data processing hosts, the primary coherency processing unit also storing a first current lock state information for the plurality of data processing hosts, the first current lock state information including a plurality of locks held by the plurality of data processing hosts. The system further includes a standby coherency processing unit storing fewer locks than the primary coherency processing unit, the locks stored by the standby coherency processing unit being a subset of locks included in the first current lock state information, the standby coherency unit configured to perform a plurality of activities of the primary coherency processing unit using the subset of locks in response to a failure of the primary coherency processing unit.

Abstract: A system and method for managing deadlocks in a database management system (DBMS) for a demultiplexed database system. The DBMS supports applications that are capable of holding and retaining locks on database resources while disassociated from worker agents. The system and method includes an application scheduler for managing requests for access to the database, and a deadlock detector for identifying a deadlock. The application scheduler assigns one worker agent to an application requesting access to a database resource, assigns a flag to an application holding a lock on the database resource while disassociated from a worker agent, and in cooperation with the deadlock detector, resolves the deadlock between the application requesting access and the flagged application holding the lock.

Abstract: A system and method for managing deadlocks in a database management system (DBMS) for a demultiplexed database system having worker agents and applications associated with, and disassociated from, the worker agents is disclosed. The DBMS of the present invention supports applications that are capable of holding and retaining locks on database resources while disassociated from worker agents. The system and method of the present invention includes an application scheduler for managing requests for access to the database, and a deadlock detector for identifying a deadlock. According to one embodiment of the present invention, the application scheduler assigns one worker agent to an application requesting access to a database resource, assigns a flag to an application holding a lock on the database resource while disassociated from a worker agent, and in cooperation with the deadlock detector, resolves the deadlock between the application requesting access and the flagged application holding the lock.