The ALDY Load Distribution System
Thomas Schnekenburger · 1995
This report describes ALDY (Adaptive Load Distribution SYstem). ALDY is a combination of system integrated and application integrated load distribution. It can be used either directly by a parallel program or by the runtime system of a parallel programming environment. The flexible object model and system independent load distribution strategies ensure that ALDY is portable over a large range of programming environments and a large range of hardware platforms. In addition to the conventional task farming paradigm used by most load distribution systems (for example, Dynamo [T ar94], and Mentat [Gri93]), ALDY supports the migration of application objects. Another ALDY feature is the realization of adaptive load distribution: Methods for adaptive load distribution are robust with respect to varying availability of system resources due to heterogeneity or processes which are generated by other users. Section 2 surveys the functions and design objectives of ALDY and describes the ALDY load distribution model. Section 3 presents the ALDY library interface. The basic concepts of the ALDY load distribution strategies are explained in section 4. In section 5, three application examples, each representing a large class of similar applications are described. Section 6 gives a summary and an outlook to our future work. 2 Concepts