Requests a reboot of the specified instances. This operation is
asynchronous; it only queues a request to reboot the specified
instances. The operation succeeds if the instances are valid and belong
to you. Requests to reboot terminated instances are ignored.
If an instance does not cleanly shut down within a few minutes, Amazon
EC2 performs a hard reboot.
For more information about troubleshooting, see Getting console output and rebooting instances
in the Amazon Elastic Compute Cloud User Guide.