Shutdown Experiment
The Shutdown experiment issues a system call to shut down or reboot the operating system on which the target is running.
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.
Linux
The Shutdown experiment issues a reboot
Linux syscall. See: reboot(2)
When this experiment is run against a host, this syscall behaves just 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.
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)
This experiment requires the SYS_BOOT
capability, which is enabled by default at installation time. See capabilities(7)
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.
Options
Parameter | Flag | Required | Default | Version | Description |
---|---|---|---|---|---|
Delay | -d int | False | 1 | 0.0.1 | The number of minutes to delay before shutting down. |
Reboot | -r | False | True | 0.0.1 | Indicates the host should reboot after shutting down. NOTE: Gremlin does not verify that the target system starts back up. |