As we saw throughout this book, OpenStack deployments run multiple services. Each service typically runs multiple Linux processes. If you find yourself troubleshooting OpenStack, you should always make sure that the expected services are up and running. This is the equivalent of making sure that everything is plugged in. Monitoring the Linux processes for each service may save you a ton of headaches when it comes to troubleshooting.
You should consider monitoring the key processes for each service. This could be as simple as configuring your monitoring service to run ps --aux on the service at regular intervals to ensure that the process is alive. Another option is to use a monitoring library that supports process monitoring and the ability to automatically restart services if they crash. Deploying methods that allow monitoring and automatic recovery of the OpenStack processes will save you time and headaches as you troubleshoot.