Modelleren van Database Systemen (Modeling of Database Systems).

摘要

Checkpointing, rollback, and recovery in a transactional database system are studied to make it possible to guarantee the reliable operation of the system. Three separate strategies for checkpointing are studied: use of a Poisson process, Following a fixed determining interval, following a fixed number of processed transactions. An important aspect is the dependence of recovery periods on the time interval between the appearance of a mistake and the last checkpoint. Three different recovery models are studied. Markov models with different checkpoint and recovery strategies are analyzed using analytical, numerical, and simulation approaches. Performance quantities, such as system availability and average queue length, of various models are compared. An important conclusion is that Poisson checkpointing cannot be used as an approximation for the more real checkpoint strategies.