Detecting Anomalies in the LCLS Workflow

The Linac Coherent Light Source (LCLS) located at SLAC National Accelerator Laboratory has been essential to over 1023 publications since 2009. The LCLS produces vast quantities of data - thousands of gigabytes per experiment. The data must be analyzed and stored at large data centers to be available to the world-wide user community. Due to the vast quantities of data flowing through the network, many abnormal data transfers remain unnoticed. This work focuses on identifying network failures that could slow down the data transfer process. This work aims to develop a diagnostic tool to detect when network transfers become anomalously slow. The tool uses an algorithm based on the hampel filter to detect poor performance and alert SLAC administrators to bottlenecks in each phase of the workflow. We will describe our experience of preparing the data and modifying the hampel filter to enhance its effectiveness. We found that applying a heuristic to the algorithm in conjunction with parsing the data along key features improved performance.