collectd

Test the configuration file and then exit

$ collectd -t

$ collectd -T

$ collectd

$ collectd -C [path/to/file]

$ collectd -P [path/to/file]

$ collectd -f

$ collectd -h

collectd [-C ] [-P ] [-f] [-s] [-h] [-v]

-C
    Specifies an alternate configuration file to use instead of the default (/etc/collectd/collectd.conf).

-P
    Specifies an alternate PID file path to use. The default is typically /var/run/collectd.pid.

-f
    Runs collectd in the foreground, preventing it from daemonizing. Useful for debugging or when running under a process supervisor.

-s
    Prints a summary of statistics (e.g., loaded plugins, number of values collected) and then exits.

-h
    Displays a brief help message with command-line options and exits.

-v
    Displays the version information of collectd and exits.

collectd is a powerful and efficient daemon that periodically collects system and application performance metrics.

It's designed to be highly extensible through a plugin architecture, allowing it to gather a vast array of data points, including CPU usage, memory consumption, network traffic, disk I/O, and much more, from various sources and applications.

The primary purpose of collectd is to enable long-term monitoring, performance analysis, and capacity planning. It operates with a focus on low resource consumption and high resolution, making it suitable for deployment on a wide range of systems, from small embedded devices to large server farms. Data collected by collectd can be stored in various backends like RRDtool, InfluxDB, Graphite, or simply written to CSV files, facilitating integration with visualization and alerting tools.

The functionality and behavior of collectd are almost entirely determined by its configuration file (collectd.conf) and the plugins enabled within it. Running collectd without a proper configuration or with no output plugins configured will result in data collection but no persistence.

While designed for low overhead, the resource consumption can increase with the number of enabled plugins and the frequency of data collection. Proper planning of data storage backend is crucial for long-term monitoring and performance.

The collectd.conf file is the central point of control for collectd. It dictates which plugins are loaded, how often data is collected, where data is stored, and various other operational parameters. Understanding and customizing this file is essential for effective use of collectd.

collectd's core strength lies in its modular plugin architecture. Plugins are dynamically loaded components responsible for data collection (input plugins, e.g., cpu, memory, network), data processing (e.g., threshold, match), and data dispatching to various storage backends (output plugins, e.g., rrdtool, influxdb, graphite, csv). This design allows users to tailor collectd to their specific monitoring needs without modifying the core daemon.

collectd was originally created by Florian Forster and first released in 2005. Its development was motivated by the need for a high-resolution, low-overhead monitoring solution that could run efficiently on various Unix-like systems. Over the years, it has evolved significantly, incorporating numerous plugins and output formats, and gaining widespread adoption in server environments and network monitoring due to its extensibility and efficiency. It remains actively maintained and developed by a community of contributors.

collectd.conf(5), rrdtool(1), systemctl(1), service(8)