Shutdown Experiment

The Shutdown experiment issues a system call to shut down or reboot the operating system on which the target is running. The reboot flag allows you to optionally tell Gremlin to restart target systems instead of shutting them down.

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Options

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Reboot Behavior

The reboot flag allows you to optionally tell Gremlin to "restart" target systems instead of shutting them down. Gremlin does not perform any validation upon target system startup after issuing a reboot. It's possible target systems never actually start back up due to the constraints within which they run. For example, issuing a reboot against target containers may trigger those containers to be reaped. This is common behavior in Kubernetes.

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Platform-specific notes

Linux

The Shutdown experiment issues a reboot Linux syscall. See reboot(2) for details.

When this experiment is run against a host, this syscall behaves as if you issued a reboot from the command line. It is considered a graceful shutdown in that it will issue a SIGTERM to all running processes, giving them a chance to terminate cleanly.

This experiment requires the SYS_BOOT capability, which is enabled by default at installation time. See capabilities(7) for details.

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Windows

The Shutdown experiment issues an ExitWindowsEx API call. Before shutting down, this system call sends the WM_QUERYENDSESSION message to all applications to determine if they can be terminated.

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Containers

When this experiment is run against a container (otherwise known as a nested PID namespace), this syscall terminates the processes immediately with a SIGKILL. See pid_namespaces(7) for details.

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