A simple process for migrating server applications to SMP:s

Abstract

A strong focus on quality attributes such as maintainability and flexibility has resulted in a number of new methodologies, e.g., object-oriented and component-based design, which can significantly limit the application performance. A major challenge is to find solutions that balance and optimize the quality attributes, e.g., symmetric multiprocessor (SMP) performance contra maintainability and flexibility. We have studied three large real-time telecommunication server applications developed by Ericsson. In all these applications maintainability is strongly prioritized. The applications are also very demanding with respect to performance due to real-time requirements on throughput and response time. SMP:s and multithreading are used in order to give these applications a high and scalable performance. Our main finding is that dynamic memory management is a major bottleneck in these types of applications. The bottleneck can, however, be removed using memory allocators optimized for SMP:s or by reducing the number of allocations. We found that the number of allocations can be significantly reduced by using alternative design strategies for maintainability and flexibility. Based on our experiences we have defined a simple guideline-based process with the aim of helping designers of server applications to establish a balance between SMP performance, maintainability and flexibility.