Netflix "Chaos Monkey" and related tools are invaluable for ensuring that cloud based applications still continue working in cases of failed services.
Microsoft is also using similar techniques, both for Windows and Azure.
"Chaos Apes" are not only random but a bit "intelligent" chaos tools that learn over time.
Chaos Engineering - MS Dev Show Podcast
GitHub - Netflix/chaosmonkey: Chaos Monkey is a resiliency tool that helps applications tolerate random instance failures.
Chaos Test Service | Microsoft Azure
"Learn how to write a service that uses Microsoft Azure Service Fabric's built-in Chaos Test to exercise your code's fault tolerance by putting a little chaos in your cluster.
Service Fabric includes a suite of tools specifically designed to test running services. You can easily induce meaningful faults and run test scenarios to exercise and validate the numerous different states and transitions a service will experience throughout its lifetime, all in a controlled and safe manner. The chaos test induces random faults - everything from moving replicas to restarting entire nodes."
Standalone Network Emulator Tool – Knock, knock! Who's there?
"NEWT (Network Emulator for Windows Toolkit) is a software-based emulator which can emulate the behavior of both wired and wireless networks using a reliable physical link, such as an Ethernet. A variety of network attributes are incorporated into the NEWT emulation model, including round-trip time across the network (latency), the amount of available bandwidth, queuing behavior, packet loss, reordering of packets, and error propagations. NEWT also provides flexibility in filtering network packets based on IP addresses or protocols such as TCP, UDP, and ICMP."