The EASY — LoadLeveler API project

With the increasing use of distributed memory massively parallel machines (MPPs) such as the IBM SP, the need for improved parallel job scheduling tools has sparked many recent developments. IBM's LoadLeveler is being used at the Cornell Theory Center, but problems exist with the current scheduling algorithm applied to the job mix on the 512-node SP. In order to address Cornell's difficulties, Joseph Skovira began to consider enhancements to LoadLeveler. At about the same time, David Lifka, developer of the EASY parallel job scheduler, began working at CTC. With Waiman Chan and Honbo Zhou of IBM LoadLeveler development, we have developed a LoadLeveler API that allows external schedulers like EASY to control the starting and stopping of jobs through LoadLeveler.