Metric graphs 101: Summary graphs

John Matson's article, the second in a series about visualizing monitoring data, delves into summary graphs as a tool for providing a snapshot of infrastructure metrics over a specific time span. It explains aggregation across time, which compresses time series data into single values, and aggregation across space, which allows metrics to be grouped by various infrastructure attributes. The piece introduces different types of summary graph visualizations: single-value summaries, toplists, change graphs, host maps, and distributions, each with distinct purposes such as highlighting key metrics, spotting outliers, tracking changes, and visualizing infrastructure at a glance. By demonstrating when to use each type of visualization, the article aims to enhance the clarity and actionability of dashboard information, setting the stage for a subsequent discussion on avoiding common pitfalls in metric visualization.