Research Paper Example Exploiting Process Lifetime Distributions for Dynamic Load Balancing Mor Harchol-Balter Allen Downey SIGMETRICS 2006

Components of a Research Paper Background Idea Work Results Next

Background Context of the research What was known before What is the question Positioning of our work Related work In this paper: Load balancing in a network Migration thought not to help [ELZ88] We can do better

Idea Something new –Algorithm –Observations Why the paper was written In this paper: Process lifetimes are heavy tailed This can be used to perform beneficial migrations

Work Collecting data Measurements Simulations Analysis In this paper: Collect data on process lifetimes Collect data on system overheads Perform simulations –Check competitiveness –Check sensitivity –Check optimality

Results Outcome of the simulations, analysis, etc. –Tables –Graphs –Interpretation In this paper: Better performance than competition Near optimal Not sensitive to system parameters

Next Extensions Shortcomings In this paper: More realistic memory usage model Take network into account And more…

The Abstract Bckgrnd Idea Work Results Next The abstract should mainly reflect the idea and results, with the necessary minimum of background and work. Say what it is, not that it exists!

Abstract #1 We measure the distribution of lifetimes of UNIX processes and propose a functional form that fits this distribution well. We use this functional form to derive a policy for preemptive migration, and then use a trace-driven simulator to compare our proposed policy with other preemptive migration policies, and with a non-preemptive load balancing strategy. We find that, contrary to previous reports, the performance benefits of preemptive migration are significantly greater than those of non-preemptive migration, even when the memory-transfer cost is high. Using a model of migration costs representative of current systems, we find that preemptive migration reduces the mean delay (queueing and migration) by 35-50%, compared to non- preemptive migration. Bckgrnd Idea Work Results Next

Abstract #2 We consider policies for CPU load balancing in networks of workstations. We address the question of whether preemptive migration (migrating active processes) is necessary, or whether remote execution (migrating processes only at the time of birth) is sufficient for load balancing. We show that resolving this issue is strongly tied to understanding the process lifetime distribution. Our measurements indicate that the distribution of lifetimes for a UNIX process is Pareto (heavy-tailed), with a consistent functional form over a variety of workloads. We show how to apply this distribution to derive a preemptive migration policy that requires no hand-tuned parameters. We use a trace driven simulation to show that our preemptive migration strategy is far more effective than remote execution, even when the memory transfer cost is high. Bckgrnd Idea Work Results Next

Abstract #3 We consider policies for CPU load balancing in networks of workstations, and specifically the use of preemptive migration (migrating active processes). We start by measuring the distribution of lifetimes of UNIX processes, and find that it is Pareto (heavy-tailed), with a consistent functional form over a variety of workloads. This distribution has the characteristic that processes that have already run for T time are expected to continue to run for an additional T time. Our policy uses this to identify those processes that will benefit from migration and justify the costs involved. We use a trace driven simulation to show that our preemptive migration strategy is far more effective than remote execution, even when the memory transfer cost is high. Bckgrnd Idea Work Results Next