Guru Meditation Reports¶
Watcher contains a mechanism whereby developers and system administrators can generate a report about the state of a running Watcher service. This report is called a Guru Meditation Report (GMR for short).
Generating a GMR¶
A GMR can be generated by sending the USR2 signal to any Watcher process with support (see below). The GMR will then be outputted as standard error for that particular process.
For example, suppose that watcher-api has process id 8675, and was run
with 2>/var/log/watcher/watcher-api-err.log. Then, kill -USR2 8675
will trigger the Guru Meditation report to be printed to
/var/log/watcher/watcher-api-err.log.
Structure of a GMR¶
The GMR is designed to be extensible; any particular service may add its own sections. However, the base GMR consists of several sections:
- Package
- Shows information about the package to which this process belongs, including version informations.
- Threads
- Shows stack traces and thread ids for each of the threads within this process.
- Green Threads
- Shows stack traces for each of the green threads within this process (green threads don’t have thread ids).
- Configuration
- Lists all the configuration options currently accessible via the CONF object for the current process.
- Plugins
- Lists all the plugins currently accessible by the Watcher service.
Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.