[k8s]组件日志级别说明

nihaogirl

The following conventions for the glog levels to use. glog is globally preferred to log for better runtime control.　　glog.Errorf() - Always an error
　　glog.Warningf() - Something unexpected, but probably not an error
　　glog.Infof() has multiple levels:
　　glog.V(0) - Generally useful for this to ALWAYS be visible to an operator
　　Programmer errors
　　Logging extra info about a panic
　　CLI argument handling
　　glog.V(1) - A reasonable default log level if you don't want verbosity.
　　Information about config (listening on X, watching Y)

　　Errors that repeat frequently that>　　glog.V(2) - Useful steady state information about the service and important log messages that may correlate to significant changes in the system. This is the recommended default log level for most systems.
　　Logging HTTP requests and their exit code
　　System state changing (killing pod)
　　Controller state change events (starting pods)
　　Scheduler log messages
　　glog.V(3) - Extended information about changes
　　More info about system state changes
　　glog.V(4) - Debug level verbosity (for now)
　　Logging in particularly thorny parts of code where you may want to come back later and check it
　　As per the comments, the practical default level is V(2). Developers and QE environments may wish to run at V(3) or V(4). If you wish to change the log level, you can pass in -v=X where X is the desired maximum level to log.