The Lagniappe programming environment

Multicore, multithreaded processors are rapidly becoming the platform of choice for designing high-throughput request processing applications. We refer to this class of modern parallel architectures as multi-[star] systems. In this dissertation, we describe the design and implementation of Lagniappe, a programming environment that simplifies the development of portable, high-throughput request-processing applications on multi-[star] systems. Lagniappe makes the following four key contributions: First, Lagniappe defines and uses a unique hybrid programming model for this domain that separates the concerns of writing applications for uni-processor, single-threaded execution platforms (single-[star]systems) from the concerns of writing applications necessary to efficiently execute on a multi-[star] system. We provide separate tools to the programmer to address each set of concerns. Second, we present meta-models of applications and multi-[star] systems that identify the necessary entities for reasoning about the application domain and multi-[star] platforms. Third, we design and implement a platform-independent mechanism called the load-distributing channel that factors out the key functionality required for moving an application from a single-[star] architecture to a multi-[star] one. Finally, we implement a platform-independent adaptation framework that defines custom adaptation policies from application and system characteristics to change resource allocations with changes in workload. Furthermore, applications written in the Lagniappe programming environment are portable; we separate the concerns of application programming from system programming in the programming model. We implement Lagniappe on a cluster of servers each with multiple multicore processors. We demonstrate the effectiveness of Lagniappe by implementing several stateful request-processing applications and showing their performance on our multi-[star] system.