Problem
What are archive monitors and how do they work?
Solution
Archive monitors are monitors attached to BACI properties automatically if and only if a few attributes of the property found in the ACS CDB are set to non-default (i.e., non-zero most of the time) values. These attributes are: archive_min_int, archive_max_int, and archive_delta. Basically what happens when these CDB characteristics are changed is that the property implementation automatically creates and maintains the lifecycle of a very special type of monitor associated with the property. Each time this monitor is triggered, information about the property is sent to a special notification channel. One can receive these events using the ArchiveConsumer classes provided by ACS.