gauge
also: metric gauge, gauge metric
Gauge is not a standard Linux term. You may be thinking of 'gauges' in monitoring tools, or possibly 'gauge' as a metric type in Prometheus-based monitoring systems that represents a single numerical value that can go up or down.
In Linux system administration and DevOps contexts, 'gauge' typically refers to a metric type used in monitoring and observability tools like Prometheus. A gauge represents a measurement that can increase or decrease over time, unlike a counter which only goes up.
Common examples of gauges include CPU temperature, memory usage in bytes, disk space available, or the number of active connections. For instance, a gauge might report that your system currently has 4,200 MB of free RAM, and five minutes later it might be 3,800 MB.
Gauges are fundamental to modern infrastructure monitoring: node_memory_MemAvailable_bytes and node_cpu_seconds_total are typical gauge metrics exposed by the Node Exporter tool for Prometheus monitoring.