Purge and modules that integrate with it bundle all log messages into a single channel named purge. This configuration form allows you to select what substreams and at which levels are allowed to log.

Id Emergency Alert Critical Error Warning Notice Info Debug
purgers
queue
diagnostics
purger_varnishbundled_a3c6f10740
purger_varnishbundled_59a3fe6a13
purger_varnishbundled_0a9233b7e9
purger_varnishbundled_76a4712fbf
purger_varnishbundled_cbfc58ddae
purger_varnishbundled_f1fe814e55