“…where c mn indicates the number of occurrences of Event n in session m. Over the years, many machine learning based methods have been proposed to employ the event-count-matrix to detect system anomalies [14], [16], [17], [18], [19], [20], [21], [22], [23]. Some of these methods use supervised learning techniques such as Logistic Regression [1], Decision Trees [2], and Support Vector Machines (SVMs) [3], while others employ unsupervised approaches such as Log Clustering [4], Principal Component Analysis [5], and the previously mentioned Invariant Miner (IM) [6].…”