puppet: delay in propagating changes is actually 4 hours

howto/puppet.md

@@ -1805,10 +1805,12 @@ The runs are executed every 4 hours, with a random (but fixed per
 host, using `FixedRandomDelay`) 4 hour delay to spread the runs across
 the fleet.
 
-Because the additional delay is fixed, changes should propagate to the
-entire Puppet fleet within 4 hours. A Prometheus alert
-(`PuppetCatalogStale`) will raise an alarm for hosts that have not run
-for more than 24 hours.
+Because the additional delay is fixed, any given host should have any
+given change applied within the next 4 hours. It follows that a change
+propagates across the fleet within 4 hours as well.
+
+A Prometheus alert (`PuppetCatalogStale`) will raise an alarm for
+hosts that have not run for more than 24 hours.
 
 ### LDAP integration
 
@@ -1921,6 +1923,10 @@ by Puppet agent to the Puppet server and writes metrics to the
 Prometheus node exporter textfile collector, in
 `/var/lib/prometheus/node-exporter`.
 
+There is an alert (`PuppetCatalogStale`) raised for hosts that have
+not run for more than 24 hours, and another (`PuppetAgentErrors`) if a
+given node has errors running its catalog.
+
 We were previously checking Puppet *twice* when we were running
 Icinga: