On-line restricted assignment of temporary tasks with unknown durations

We consider load balancing of temporary tasks on m machines in the restricted assignment model. It is known that the best competitive ratio for this problem is Θ( √ m). This bound is not achieved by the greedy algorithm whose competitive ratio is known to be Ω(m 2 3 ). We give an alternative analysis to the greedy algorithm which is better than the known analysis for relatively small values of m. We also show that for a small number of machines, namely m ≤ 5, the greedy algorithm is optimal.