What are some alternatives?
When comparing Munin and Datadog, you can also consider the following products
Zabbix - Track, record, alert and visualize performance and availability of IT resources
LogicMonitor - LogicMonitor is the SaaS performance monitoring platform for the world's best IT teams. Deploy Fast, Monitor More, Improve Ops.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
Icinga - Icinga is a fork of Nagios and is backward compatible.
Sumo Logic - Sumo Logic is a secure, purpose-built cloud-based machine data analytics service that leverages big data for real-time IT insights
Spiceworks Help Desk - Help desk software features that work for IT