Consul

Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. Register external services such as SaaS providers as well

     

linux windows osx open-source service-discovery go monitoring

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

Monit

An open source utility for managing and monitoring processes, programs, files, directories and filesystems

     

linux osx open-source monitoring process-mgmt c

testssl.sh

A command-line tool which checks a server's service on any port for the support of TLS/SSL ciphers, protocols as well as some cryptographic flaws. It's designed to provide clear output for your "is this good or bad" decision.

     

linux osx open-source security shell