11.12. The Watchman Tool
The Watchman tool is a daemon that is used to protect your OpenShift Enterprise instance against common issues found by Red Hat
. The Watchman tool solves these common issues autonomously, and includes the following built-in features:
- Watchman searches cgroup event flow through syslog to determine when a gear is destroyed. If the pattern does not match a clean gear removal, the gear will be restarted.
- Watchman monitors the application server logs for messages hinting at out of memory, then restarts the gear if needed.
- Watchman compares the user-defined status of a gear, then the actual status of the gear, and fixes any dependencies.
- Watchman searches processes to ensure they belong to the correct cgroup. It kills abandoned processes associated with a stopped gear, or restarts a gear that has zero running processes.
- Watchman monitors the usage rate of CPU cycles and restricts a gear's CPU consumption if the rate of change is too aggressive.
Watchman capabilities can be expanded with plug-ins. Consult your system administrator for configuring Watchman or see the OpenShift Enterprise Administrators Guide at https://access.redhat.com/site/documentation for more information.
