Possibly from changes made to secure rsync?  I've seen a few of these so I thought I would forward.  Cheers!
---------- Forwarded message ---------
From: Cron Daemon <root@stat1005.eqiad.wmnet>
Date: Tue, Dec 11, 2018 at 7:49 AM
Subject: Cron <root@stat1005> /usr/local/bin/published-datasets-sync -q
To: <root@stat1005.eqiad.wmnet>


rsync: failed to connect to thorium.eqiad.wmnet (2620:0:861:108:10:64:53:26): Connection timed out (110)
rsync: failed to connect to thorium.eqiad.wmnet (10.64.53.26): Connection timed out (110)
rsync error: error in socket IO (code 10) at clientserver.c(125) [sender=3.1.2]


--
Chase Pettet
chasemp on phabricator and IRC