Chef
Configuration management tool which uses a pure-Ruby, domain-specific language (DSL) for writing system configuration recipes. Supports Linux, UNIX, Windows, and AIX as first-class citizens for management.
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ConDep
ConDep is a open source infrastructure configuration and deployment DSL (Domain Specific Language) specifically targeted to (but not limited to) the Windows Server platform. If your familiar with tools like Chef and Puppet, ConDep does very much the same, but with native support for Windows.
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Puppet
Puppet is a tool designed to manage the configuration of Unix-like and Microsoft Windows systems declaratively.
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SaltStack
Salt is a powerful and different approach to infrastructure management, by focusing on high speed communications between large number of systems, and can perform orchestration, remote code execution and much more.
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Supervisor
Supervisor can manage application processes. It can start and stop a group of processes, restart processes if any of them terminate (keep-alive), start multiple instances of the same process (process pooling), automatically manage PID files, and much more! Very useful if you need to manage multiple processes for your application.
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Vaurien
A Chaos Monkey for TCP, it randomly disconnects or stalls TCP connections in your application to test application tolerance and high availability. Makes sure you correctly handle these unexpected events
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