Performance of Internet Applications on Modern Servers

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The emergence of low-cost, feature-rich consumer computing devices like tablets and smart phones, coupled with a diversifying set of Internet-based "services" has resulted in a substantial infrastructure of computer servers and networks. This infrastructure incurs large capital expenses to build and high operating expenses to run. In the mid-1990s, both industry and academia devoted considerable effort to analyze Internet performance, to both increase performance and to provide more cost-effective solutions. Yet since the late 1990s, topics like functionality have received much more attention than performance, as the horizontal scalability of many Internet applications made "throwing more hardware" at a performance or scalability issue the de facto solution. Understanding and improving Internet application performance has re-emerged as an important problem, due to a realization that the "throwing more hardware" approach not only increases capital and operating expenses, but also increases the environmental footprint of IT infrastructure. In addition, the design of computer servers has changed considerably since performance evaluation was last a widely popular topic. As an example, physical limitations have prevented processor manufacturers from continuing to increase the clock frequency to achieve reasonable performance gains with each new generation of processor. Instead, increasing the number of processor cores has become the standard practice. While some applications were (re)designed to take advantage of “multi-core servers”, others are only now being augmented. Furthermore, knowledge about the behavior of servers with single-core processors is still the "conventional wisdom" used to operate modern multi-core systems. This leads to the deployment of more servers (thus increasing capital expenses) than are needed to support a given load. As servers use a disproportionately high amount of power when lightly utilized, this increases operating costs and IT’s environmental footprint. The proposed research is to determine and demonstrate how to fully exploit the capabilities of modern servers, so that consumer requests can be satisfactorily served with a minimal financial and environmental cost. The results could directly benefit Canadian service providers like Bell and Telus. This program will involve three research threads: 1. Experimental evaluation of Web servers on modern computer servers. (1 PhD student) 2. Experimental evaluation of an Intrusion Detection System (IDS) on modern computer servers. (1 PhD student) 3. Characterization and modeling of Internet traffic. (2 Masters students) Threads #1 and #2 will explore how to maximize the use of multi-core servers for realistic Internet workloads. Synthetically generated workloads, or replayed traces will place controlled amounts of workload on the servers being tested. Extensive instrumentation of the servers will provide the data needed to establish new “conventional wisdom” on how to configure, manage and operate Internet applications, such that a desired Quality of Service can be obtained while maximizing the use of the servers. The initial research (Thread #1) will focus on Web servers, since the ability to influence how these are operated in practice could have a significant impact. Thread #2 relates to Internet security applications, which are expected to be of considerable long term importance. The Internet monitoring infrastructure in place at the University of Calgary and operated by the applicant motivates this thread. Thread #3 will occur in parallel to the other threads. By collecting, analyzing and modeling actual Internet traffic, the realism of the workloads needed in Threads #1 and #2 can be improved and the impact of the research increased.