Title: An Admission Control Paradigm for Real-Time Databases
Author: Azer Bestavros and Sue Nagy
Date: January 11, 1996

Abstract:

We propose and evaluate an admission control paradigm for RTDBS, in
which a transaction is submitted to the system as a pair of processes:
a primary task, and a recovery block. The execution requirements of
the primary task are not known a priori, whereas those of the recovery
block are known a priori. Upon the submission of a transaction, an
Admission Control Mechanism is employed to decide whether to admit or
reject that transaction. Once admitted, a transaction is guaranteed to
finish executing before its deadline. A transaction is considered to
have finished executing if exactly one of two things occur: Either its
primary task is completed (successful commitment), or its recovery
block is completed (safe termination). Committed transactions bring a
profit to the system, whereas a terminated transaction brings no
profit. The goal of the admission control, and scheduling protocols
(e.g., concurrency control, I/O scheduling, memory management)
employed in the system is to maximize system profit.  We describe a
number of admission control strategies and contrast (through
simulations) their relative performance.