Monit

Monit (man) is a free, open-source process supervision tool for Unix and Linux. Monit can restart a process automatically if process dies or monitor process characteristics, such as memory or cpu cycles and alert or execute and action. Monit only support alert messages by email. Monit support monitoring cpu, memory, swap usage and loadavg among others.

Installation

• Installation macOS: brew install monit
• Linux: apt install monit
• Access: http://localhost:2812/ (admin/monit)

• Config file: /etc/monit/monitrc (monit -t) to verify configuration file

set daemon 120 By default configured to check services every 120 seconds

Review examples: https://mmonit.com/wiki/Monit/ConfigurationExamples

• Logs: /var/log/monit.log
• Command: monit status
• Restart Monit service: systemctl restart monit.service && systemctl status monit

Example

/etc/monit/monitrc

#  check system $HOST
#    if loadavg (1min) per core > 2 for 5 cycles then alert
#    if loadavg (5min) per core > 1.5 for 10 cycles then alert
#    if cpu usage > 95% for 10 cycles then alert
#    if memory usage > 75% then alert
#    if swap usage > 25% then alert

Related commands

• logcheck
• glances

See also

• monit, monit -t, monit status, /etc/monit/monitrc
• Monitoring: Prometheus, Cacti, monit, munin, RRDtool, Zabbix, Netdata, Nagios, Check MK, Icinga, Pingdom, OpsGenie and Datadog, Opsgenie, PRTG, Checkmk
• Monitoring: On call, Monitoring software, Monitoring services, Resource monitoring, Metric colletion tools, network monitoring, SLA Management Monitoring Tools, Alarm/Alert, Resource starvation, Alerts and notifications, Monitoring Kubernetes, VictoriaMetrics, Sensu, LogicMonitor, Distributed tracing, Datadog Monitors

https://mmonit.com/monit/documentation/monit.html#ALERT-MESSAGES