A competitive algorithm for minimizing weighted flow time on unrelatedmachines with speed augmentation

Jivitej S. Chadha, Naveen Garg, Amit Kumar, V. N. Muralidhara
2009 Proceedings of the 41st annual ACM symposium on Symposium on theory of computing - STOC '09  
We consider the online problem of scheduling jobs on unrelated machines so as to minimize the total weighted flow time. This problem has an unbounded competitive ratio even for very restricted settings. In this paper we show that if we allow the machines of the online algorithm to have more speed than those of the offline algorithm then we can get an O((1 + −1 ) 2 )-competitive algorithm. Our algorithm schedules jobs preemptively but without migration. However, we compare our solution to an
more » ... ine algorithm which allows migration. Our analysis uses a potential function argument which can also be extended to give a simpler and better proof of the randomized immediate dispatch algorithm of Chekuri-Goel-Khanna-Kumar for minimizing average flow time on parallel machines.
doi:10.1145/1536414.1536506 dblp:conf/stoc/ChadhaGKM09 fatcat:hbylkj6ye5hp7daipvk4ynhyea