Difference between Cumulative and Point-in-time counters
Cumulative Metrics' (that increase with time and can be recorded for a period (like 'Key_reads', 'Maximum no. of Connections that Ever Was') are calculated differently instead of point-in-time metrics (like 'Server Availability', 'Currently Running Threads').
For 'cumulative metrics', MONyog will send alerts if thresholds are crossed for last collection interval.
For 'point-in-time' metrics, MONyog will send alert only based on 'Current' values (for instance current no. of connections is close to Max Allowed Connections - there is nothing more to consider!).
NOTE: Security, Excessive Privileges, InnoDB Deadlocks and Replication counters are available only in MONyog Ultimate.