Online scheduling with a buffer on related machines

Online scheduling with a buffer is a semi-online problem which is strongly related to the basic online scheduling problem. Jobs arrive one by one and are to be assigned to parallel machines. A buffer of a fixed capacity K is available for storing at most K input jobs. An arriving job must be either assigned to a machine immediately upon arrival, or it can be stored in the buffer for unlimited time. A stored job which is removed from the buffer (possibly, in order to allocate a space in the buffer for a new job) must be assigned immediately as well. We study the case of two uniformly related machines of speed ratio s ≥ 1, with the goal of makespan minimization. Two natural questions can be asked. The first question is whether this model is different from standard online scheduling, that is, is any size of buffer K > 0 already helpful to the algorithm, compared to the case K = 0. The second question is whether there exists a constant K, so that a larger buffer is no longer bene�...

• Type: Journal
• Year: 2010
• Where: JCO
• Authors: György Dósa, Leah Epstein
• Keywords: JCO 2010, Larger Buffer, Machines, Online Scheduling