Abstract: An apparatus for and method of implementing a cluster lock processing system having a relatively large number of commodity cluster instruction processors which are managed by a highly scalable, off the shelf communication processor. Because the commodity processors have virtually no system viability features such as memory protection, failure recovery, etc., the communication processor assumes the responsibility for providing these functions. The low cost of the commodity cluster instruction processors makes the system almost linearly scalable. Furthermore, having a fully scalable communication processor ensures a completely scalable system. The cluster/locking, caching, and mass storage accessing functions are fully integrated into a single hardware platform. The architecture may be implemented using any of a wide variety of proprietary or non-proprietary operating system environments.

Abstract: An apparatus for and method of implementing a cluster lock processing system having a relatively large number of commodity cluster instruction processors which are managed by a highly scalable, off the shelf communication processor. Because the commodity processors have virtually no system viability features such as memory protection, failure recovery, etc., the communication processor assumes the responsibility for providing these functions. The low cost of the commodity cluster instruction processors makes the system almost linearly scalable. Furthermore, having a fully scalable communication processor ensures a completely scalable system. The cluster/locking, caching, and mass storage accessing functions are fully integrated into a single hardware platform.

Abstract: Method and apparatus for tracking messages and transactions communicated between a number of users and a number of hosts, where the hosts are executing concurrent applications. During a first user session, a first user communicates with a first host. A counter associated with the first user session is incremented when the application creates an output message. The counter is decremented when the output message is released to the first user. A flag associated with the first user session is set and the counter is incremented once the flag is set, if an input message or committing transaction is received from the first user. The flag is cleared and the counter is decremented when the input message or committing transaction is processed by the concurrent application. The counter being decremented indicates there are no dependencies during the first user session with regard to the output message, input message, or committing transaction.

Abstract: Method and apparatus for providing backup memory storage for audit trail data within a computer system having a main memory storage, a non-volatile memory storage, and backup memory storage. The computer system executes a number of transaction programs which generate audit trail entries. As the audit trail entries are generated, a portion of the audit trail entries are stored in a portion of the main memory storage to create an audit trail. The audit trail entries are accumulated in the portion of the main memory storage until a request is received to write the portion of the main memory storage to a corresponding portion of the non-volatile memory. Subsequent portions of the audit trail entries are accumulated in subsequent portions of the main memory storage.

Abstract: Method and apparatus for managing the allocation and release of memory space within a number of files shared by a number of hosts in a data processing system. A number of allocate and release tables are provided which are accessible by the number of hosts for managing the allocation and release of space within the number of files. Each one of the number of allocate and release tables corresponds to one of the number of files and provides a file location, file size, and indication to the number of hosts of which of the number of blocks within the file have been allocated and which of the number of blocks have been released. Any host may allocate one or more of the number of blocks to store messages created or received by the host by determining from the allocate and release tables which one or more of the number of blocks within one of the number of files are available.

Abstract: A data processing system including a first and second host, a first and second outboard file cache connected to the first host, and a first and second secondary storage device connected to the first host. The system operation includes the first host reading file data from the first or second secondary storage device after the data is cached on both the first and second outboard file caches. File data is updated by writing to both first and second outboard file caches. File data is destaged by writing data from the first outboard file cache only, to first and second secondary storage devices. Failure of a single outboard file cache is handled by the first host not reading and writing to the failed outboard file cache. Site-wide failure of first host, first outboard file cache, and first secondary storage device is handled by establishing communication from second host to both second outboard file cache and second secondary storage device and resuming processing.

Abstract: A computer system having dual outboard devices for generating audit trail sequence numbers and performing file locking. One embodiment includes a master and a slave outboard device, where lock request handling includes a lock request first sent to the master, lock grant awaited, followed by a request sent to the slave. Unlock request handling includes sending an unlock request to slave first, followed by sending an unlock request to the master. Obtaining a system sequence number includes always reading the slave outboard device, then reading the master outboard device. The computer system includes a method for switching host processors from a single outboard device mode to a dual outboard device mode and back again in the event of failure of one of the outboard devices.

Abstract: A system and method are described for caching files of data in a cache which is beyond the input/output boundary of a host. A host references a file with file access commands containing a logical file-identifier and a logical offset into the file. An outboard file cache coupled to the input/output section of the host receives the file access commands. The outboard file cache is transparent to users who program the host. Generation of input/output channel programs and mapping the data referenced to a physical address in secondary storage are eliminated when the referenced data is present in the cache. A file descriptor table in the outboard file cache identifies the logical portions of the logical files which are present in the cache. If the data referenced by the logical file-identifier and logical offset in a file access command is present in the outboard file cache, the data is transferred from the outboard file cache to the host memory.

Abstract: A system for concurrent processing of queries and transactions against a shared database. The system includes multiple processors wherein a processor is available for processing queries and another processor is available for concurrently processing transactions. A query buffer is established for performing the query search while the data accessed by transactions is available in a database cache. Control logic in a database management system distinguishes between transactions and queries and initiates file-read control for reading the file containing the database. File-read control contains logic for logical sequential reading and logical non-sequential reading of the file. Control structures provide a means for control over the load that the query is allowed to place on the system.

Abstract: A transaction processing audit and recovery system is disclosed. After processing a transaction, an audit manager logs in audit records only changed blocks of data of a segment of a database. Upon failure of database backing storage, a prior copy of the database is reloaded to database backing storage that is available and a recovery manager reads the audit records and copies the changed blocks back to the database backing storage. An outboard file cache system is used in conjunction with the recovery manager to recover the database. The outboard file cache provides cache storage for segments of the database and writes non-contiguous blocks of one or more segments as directed in a single input/output request initiated from the recovery manager.

Abstract: A multiprocessor data processing system is implemented with processors, each of which may request for a temporary time the exclusive lock on an object which is stored on a data base. To achieve this a lock processor synchronizes the locking and unlocking of the objects. The requesting processor directs the storage of the object from the data base into a selected high performance storage unit, where it has exclusive rights to modify or write into the object until the object is unlocked by the processor. An audit tape or disk records all modifications made to any object during a transaction. A non-volatile cache memory is inserted in the audit trail to store a before-look image of the object that resides in the high performance storage unit. Data compaction occurs by comparison of the before-look image with an after-look image to provide a difference image, which is supplied to an audit buffer that is coupled to the audit tape.