We treat a single-server vacation queue with queue-length dependent vacatio
n schedules. This subsumes the single-server vacation queue with exhaustive
service discipline and the vacation queue with Bernoulli schedule as speci
al cases. The lengths of vacation times depend on the number of customers i
n the system at the beginning of a vacation. The arrival process is a batch
Markovian arrival process (BMAP). We derive the queue-length distribution
at departure epochs. By using a semi-Markov process technique, we obtain th
e Laplace-Stieltjes transform of the transient queue-length distribution at
an arbitrary time point and its limiting distribution.