Noticed that one of my relays (OhNoAnotherRelay02) is showing as off-line.  Looking at the logs, I see a bunch of these messages:

Oct 18 08:39:16.000 [notice] Channel padding timeout scheduled 143041ms in the past. Oct 18 08:39:21.000 [notice] Channel padding timeout scheduled 156925ms in the past. Oct 18 08:39:24.000 [notice] Channel padding timeout scheduled 168712ms in the past. Oct 18 08:39:25.000 [notice] Channel padding timeout scheduled 166895ms in the past. . . . Oct 18 10:18:48.000 [notice] Channel padding timeout scheduled 194581ms in the past. Oct 18 10:35:22.000 [notice] Channel padding timeout scheduled 216311ms in the past. Oct 18 10:35:30.000 [notice] Channel padding timeout scheduled 224267ms in the past.

What's the cause of this.

I used this downtime as an excuse to do a bunch of upgrades and a re-boot.

Cheers.