You see alerts triggered by server statistics monitoring thresholds.
During each threshold interval, if an error or warning occurs, it is reported at the end of an evaluation period. For example, if your threshold interval is set to five minutes, and the evaluation frequency is set to five times per interval, the first trouble item may appear after one minute has elapsed, but will not be reported more than once per threshold interval. If competing threshold levels occur during same evaluation cycle, the highest severity is reported.
Each time you refresh your browser or open the Monitoring page, monitoring statistics are updated. The report, however, is updated only at the end of an evaluation period.
The list of trouble items shows the error/warning level, time, property name, and configuration details for each item reported.