Analyzing Computer System Performance with Perl::PDQ [electronic resource] / by Neil J. Gunther.

Part I Preliminary Concepts -- Why Queues Rule Performance Analysis -- Measurement Tools and Techniques -- Time - The Zeroth Performance Metric -- Part II Basic Queueing Theory for PDQ -- Getting the Jump on Queueing -- Queueing Systems for Computer Systems -- Linux Load Average -- Performance Bounds and Log Jams -- Part III Practical Application of PDQ -- Pretty Damn Quick|A Slow Introduction -- Multicomputer Analysis with PDQ -- How to Scale an Elephant with PDQ -- Client/Server Analysis with PDQ -- Web Application Analysis with PDQ -- Virtual Machine Analysis with PDQ -- Part IV Appendices -- Thanks for No Memories -- Compendium of Queueing Equations -- Units and Abbreviations -- Perl PDQ Manual -- Solutions to Selected Exercises.

To solve performance problems in modern computing infrastructures, often comprising thousands of servers running hundreds of applications, spanning multiple tiers, you need tools that go beyond mere reporting. You need tools that enable performance analysis of application workflow across the entire enterprise. That's what PDQ (Pretty Damn Quick) provides. PDQ is an open-source performance analyzer based on the paradigm of queues. Queues are ubiquitous in every computing environment as buffers, and since any application architecture can be represented as a circuit of queueing delays, PDQ is a natural fit for analyzing system performance.   Building on the success of the first edition, this considerably expanded second edition now comprises four parts. Part I contains the foundational concepts, as well as a new first chapter that explains the central role of queues in successful performance analysis. Part II provides the basics of queueing theory in a highly intelligible style for the non-mathematician; little more than high-school algebra being required. Part III presents many practical examples of how PDQ can be applied. The PDQ manual has been relegated to an appendix in Part IV, along with solutions to the exercises contained in each chapter. Throughout, the Perl code listings have been newly formatted to improve readability. The PDQ code and updates to the PDQ manual are available from the author's web site at www.perfdynamics.com