A healthy running server prints the following messages, approximately every 16MB of redo log:

2017-09-10 13:56:21 140493990914816 [Note] InnoDB: Read redo log up to LSN=139157068288
2017-09-10 14:46:42 140496077253376 [Note] InnoDB: Read redo log up to LSN=139173845504
2017-09-10 14:57:45 140496085437184 [Note] InnoDB: Read redo log up to LSN=139190622720
2017-09-10 15:36:40 140496110553856 [Note] InnoDB: Read redo log up to LSN=139207399936
2017-09-10 15:39:12 140496496207616 [Note] InnoDB: Read redo log up to LSN=139224177152
2017-09-10 15:59:44 140496504600320 [Note] InnoDB: Read redo log up to LSN=139240954368
2017-09-10 16:27:30 140493987277568 [Note] InnoDB: Read redo log up to LSN=139257731584
2017-09-10 16:40:22 140496496207616 [Note] InnoDB: Read redo log up to LSN=139274508800
2017-09-10 16:55:52 140496335579904 [Note] InnoDB: Read redo log up to LSN=139291286016
2017-09-10 17:45:49 140496336186112 [Note] InnoDB: Read redo log up to LSN=139308063232
2017-09-10 18:25:37 140496496207616 [Note] InnoDB: Read redo log up to LSN=139316947456
2017-09-10 18:51:12 140496496207616 [Note] InnoDB: Read redo log up to LSN=139341617664

No recovery is in progress, the server is receiving connections and properly working.

innodb_log_archive=ON
log_warnings=2