collector
also: agent, forwarder, shipper
A program or process that gathers, aggregates, and processes data from multiple sources—commonly used in monitoring systems to collect metrics, logs, or events from distributed systems.
In Linux systems, a collector is typically a daemon or scheduled task that pulls or receives data from various sources and centralizes it for storage or analysis. Collectors are fundamental components of monitoring and observability stacks.
Common examples include metric collectors like telegraf or collectd, which gather CPU, memory, disk, and network statistics from a host; log collectors like filebeat or fluentd, which aggregate log files from multiple applications; and trace collectors that capture distributed system calls.
Collectors typically run continuously in the background, use minimal resources, and forward collected data to central systems (databases, log aggregators, or time-series stores) for visualization and alerting. For example, collectd might collect system metrics every 10 seconds and send them to a Prometheus or InfluxDB database for monitoring.