WebMon: A performance profiler for web transactions

We describe WebMon, a tool for correlated, transaction-oriented performance monitoring of web services. Data collected with WebMon can be analyzed from a variety of perspectives: business, client, transaction, or systems. Maintainers of web services can use such analysis to better understand and manage the performance of their services. Moreover WebMon's data will enable the construction of more accurate performance prediction models for web services. Current web logging techniques create a log file per server making it difficult to correlate data from log files with respect to a given transaction. Additionally, data about the quality of service perceived by the client is missing entirely. WebMon overcomes these limitations by providing heterogenous instrumentation sensors and HTTP cookie-based correlators. In this paper, we present the design and implementation of of WebMon and our experience in applying WebMon to an HP Library web service.