Simian Army

Simian Army 2018-02-12T20:31:59+00:00


The Simian Army is an open-source IT tooling developed by Netflix to improve availability and reliability by handling various cloud computing issues and challenges. It is built with a variety of Simian Army Monkey tools to help ensure network health, promote efficient traffic and locate security problems.

The Simian Army runs on the Amazon Web Services (AWS) infrastructure.

In creating the Simian Army, Netflix began with Chaos Monkey, described as a tool that targets individual production instances and disables them to provide more stable and consistent operations. Netflix then introduced Latency Monkey, which simulates partial network downtime, and Conformity Monkey, which enforces network consistency. Janitor Monkey eliminates excess digital clutter in a cloud environment, and Doctor Monkey performs network health checks.

Other tools, like Security Monkey, 10-18 Monkey and Chaos Gorilla are also part of this ground-breaking IT system.

Latency Monkey induces artificial delays in our RESTful client-server communication layer to simulate service degradation and measures if upstream services respond appropriately.

Conformity Monkey finds instances that don’t adhere to best-practices and shuts them down.

Doctor Monkey taps into health checks that run on each instance as well as monitors other external signs of health to detect unhealthy instances.

Janitor Monkey ensures that our cloud environment is running free of clutter and waste.

Security Monkey is an extension of Conformity Monkey. It finds security violations or vulnerabilities, such as improperly configured AWS security groups, and terminates the offending instances.

10–18 Monkey detects configuration and run time problems in instances serving customers in multiple geographic regions, using different languages and character sets.

Chaos Gorilla is similar to Chaos Monkey, but simulates an outage of an entire Amazon availability zone.