The InternalTelemetry plugin is for internal use only. It is therefore undocumented, and its use is disencouraged, as API compatiblity will **not be guaranteed**.
The gist of it is: when debug_level of logger is enabled to 3 or greater, considered internal-only supported log levels, it’ll be loaded by default.
Against a specific point of time, which will be by default the session initialization, but can be set by the end user in $http_init_time, different diff metrics can be shown. The “point of time” is calculated using the monotonic clock.