%Monitor class to collect and manage part of the Monitor History Database.
This class collects the SYS.History.SysData samples for the System Usage Metrics,
as defined in the Usage and Database classes, at somewhat longer intervals than the
History class (default of 5 minutes).
By default the SysData collection is kept for 7 days and then purged. The number of days to keep may be modified using SYS.History.PerfData:SetPurge() The SysData samples can be automatically rolled up at the end of each day into Hourly (SYS.History.Hourly) or Daily (SYS.History Daily) summaries, which can be kept for longer periods.
Keep a list of properties for 'counter' type user classes
Keep track of last date to see of it's time to purge/summarize
Keep count of consecutive errors
Keep a copy of the last PerfData sample for calculating deltas
Length of last sample
Status of last sample
Keep a copy of the last UserSys sample for calculating deltas
Get the basic SYS.History.SysData sample for the Monitor History Database. This method also handles purging and accumulation of the Detail metrics into the long term database (SYS.History.Hourly and SYS.History.Daily).
Initialize property values