During a critical outage event this weekend, icinga sent alert pages via smsglobal to virtually all of our operations personnel, as we were mostly all in our awake_hours windows. I happened to copy one such line to irc at the time, which was this:
 SERVICE NOTIFICATION: bblack;text-lb.esams.wikimedia.org;LVS HTTP IPv4;CRITICAL;notify-by-sms-gateway;Connection refused
When I observed icinga.log at the time, I am definitely sure there was a block of such matching lines for everyone. However, @Joe @akosiaris and @faidon confirmed on IRC they never received these texts, indicating probably an smsglobal delivery failure specific to our EU ops. @BBlack and @Gage did receive the pages for sure.
Additionally, all log lines of the paging event, including the one pasted above, are gone from our icinga logs. There seems to be a history gap after rotation between icinga.log.1 and icinga.log, which covers this timeframe. I'll file a separate task about that...