Software Fault-Tolerance with Off-the-Shelf SQL Servers
"Software Fault-Tolerance with Off-the-Shelf SQL Servers" by P. Popov, L. Strigini, A. Kostov,
V. Mollov and D. Selensky appeared in the Proc. of 3rd International Conference COTS-Based Software
Systems, Redondo Beach, CA, USA, February 2004, published by
Springer, in the Lecture Notes in Computer
Science Series. The paper abstract is given below. The full text is available
for download as a .pdf file.
Abstract
With off-the-shelf software, software fault tolerance is almost the only means
available for assuring better dependability than the off-the-shelf software offers,
without the much higher costs of bespoke development or extra V&V. We report
our experience with an experimental setup we have developed with off-the-shelf
SQL database servers. First, we describe the use of a protective wrapper to mask
the effects of a bug in one of the servers, without depending on an adequate fix
from the vendors. We then discuss how to combine the diverse off-the-shelf servers
into a diverse modular redundant configuration (N-version software or N-self-checking
software). A wrapper guarantees the consistency between the diverse replicas of
the database, serving multiple clients, by restricting the concurrency between
the client transactions We thus show that diverse modular redundancy with protective
wrapping is a viable way of achieving fault-tolerance with even complex off-the-shelf
components, like database servers.
Page maintained by: Peter Popov
Last modified: 2 December 2004