collectd

A daemon that collects system performance statistics periodically, and provides tons of plugins to store and analyze these values

     

linux windows osx open-source monitoring c

Gerrit

A Web based code review and project management system for Git projects

     

linux windows osx open-source scm java

Instrumental

Instrumental is a real-time, high-scale application and server monitoring tool with intelligent alerts, a powerful query language, and free development accounts.

     

linux windows oxs free metrics commercial metrics monitoring visualization php ruby python net java nodejs

jclouds

A Java Library for controlling cloud resources, with various plugins for many popular cloud providers.

     

linux windows osx open-source cloud-paas java

jmxtrans

Plugs Java VM statistics via JMX to various backend monitoring tools

     

linux windows osx open-source monitoring java

KairosDB

KairosDB is a fast distributed scalable time series database written on top of Cassandra. RESTful JSON-based query/results. Includes flot-based visualization.

     

linux windows osx open-source metrics visualization java cassandra

Logstash

A modern tool for managing events and logs, with an ElasticSearch backend which allows a high degree of searching and filtering. It includes a shipper in remote systems, indexer in the aggregator machine, and a Web UI.

     

linux windows osx open-source monitoring java

Metrics

Captures JVM and application-level metrics for Java

     

linux windows osx open-source monitoring java

Sentry

Automate error tracking to find and fix issues before your users even experience a crash. Sentry is open-source, real-time, and loved by 100,000 developers around the world.

     

osx windows linux open-source errors nodejs ruby python php java monitoring

Zabbix

An open source, enterprise-class monitoring framework

     

linux windows osx open-source monitoring c