Virtual memory management for transaction processing systems

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6472855

Eppinger, J L

To support failure atomicity and permanence, transaction processing systems store data in recoverable storage. Recoverable storage is commonly implemented using a combination of volatile, non-volatile, and stable storage. Data are maintained in non-volatile storage over the long term. While data are being processed, they are cached in volatile, primary memory. Stable storage is used for a log that permits operations to be undone or redone. Transaction processing systems typically implement recoverable storage themselves, using virtual memory or specially mapped physical memory for volatile buffer space. However, many advantages are obtained if the operating system provides recoverable virtual memory: data are mapped into virtual memory and thereby accessed more conveniently; the operating system's fast address translation and paging components provide increased performance; the amount of primary memory allocated to buffering data adapts to system load allowing double paging to be eliminated. Recoverable virtual memory does not preclude the use of other transaction processing techniques. Virtual memory support can be provided for transaction processing systems. Some reviews are made of novel hardware and special purpose implementations of recoverable virtual memory. Described in depth is a system which implements recoverable virtual memory: the Camelot Transaction Processing Facility. The Camelot implementation utilizes a general software approach that does not use any special purpose hardware (other than standard virtual memory hardware). The implementation is portable: it runs on IBM RTs, Suns, and Vaxes, including shared memory multiprocessor Vaxes. A variety of logging and locking techniques are used. Other specialized implementations of recoverable virtual memory impose severe restrictions on users. The use of recoverable virtual memory for general purpose transaction processing systems is demonstrated.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (USA)
• OSTI ID: 6472855
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990200* -- Mathematics & Computers
990300 -- Information Handling
ARRAY PROCESSORS
COMPUTER ARCHITECTURE
CONTROL SYSTEMS
DATA PROCESSING
DATA-FLOW PROCESSING
INFORMATION RETRIEVAL
INFORMATION SYSTEMS
MEMORY DEVICES
MEMORY MANAGEMENT
ON-LINE CONTROL SYSTEMS
ON-LINE SYSTEMS
PROCESSING
PROGRAMMING