Sensu is an open source monitoring framework written in Ruby. The project was started in 2011 by Sean Porter from Cariboo, British Columbia. (Canada) Sean has worked for Heavy Water Operations LLC in Portland, Oregon (USA) since 2013. As a result of a $2.5 million investment by the Foundry Group in the beginning of 2017, Heavy Water Operations has changed its name to Sensu, Inc. and doubled its number of employees. Several well-known open source luminaries now work there including Jason Dixon, the founder of the largest monitoring conference in the USA: „Monitorama“ and author of the book „Monitoring with Graphite“ published by O’Reilly.

Sensu features an extraordinarily flexible architecture:

(a) All important components such as queueing, database, API, dashboard, configuration and graphing can be separated from the core system, which is responsible for scheduling and the triggering of handlers, and spread across multiple nodes, scaling to any size desired.

(b) Sensu is compatible with Nagios Check plug-ins. In addition to the ability to collect true metrics in a time series database, conventional checks from the community can be used as well. Migrations from Nagios and co. to Sensu are thus rendered flexible and easy to realize.

Sensu fills a critical niche in the open source monitoring landscape. Especially cloud workloads and VMs which are replicated hundreds of times using OpenStack or Azure are included without any manual intervention. As opposed to purely metric-based tools such as Prometheus, Sensu’s Nagios compatibility delivers a decisive advantage to data center operators.

becon is committed to evaluating and recommending open source monitoring tools openly and objectively, and our partnership with Sensu changes none of that. Any of the time-tested tools Nagios, Naemon, Icinga2, Check_MK, Zabbix, openNMS, as well as the two upstarts Prometheus and Sensu, can represent the right choice for our clients, depending on their individual requirements.

Our whitepaper „Open Source Monitoring Guide“, which will compare and contrast the strengths and weaknesses of each of the most popular tools, will be available soon.