How to count IM Logs?
I have some problems to understand the counting method for IM Logs. The log summary aspect counts about 50000 logs.
If I add all property logs from the log template aspects I get ~10.000. I guess the IM shows the number of property logs.
In future our customer wants to use this template for ~25.000 property logs.
BH_1s_60d is type OPC, the other are IM Log with average calculation.
In the manual the maximum number is given with 30.000 logs and 20.000 logs.
How many logs result from that template at 25000 logs?
Is it 25000, -or 75000? Can the system manage this in one IM Server?
Did you search all Log Templates? E.g. 800xA for Advant Master have TTD log templates created in the Control Structure, counting from Library Structure alone will miss those and return a too low count.
The Plant Explorer's Find Tool will easily find them for you if you set to search for:
b) Category = Log Template
I read the System Guide as an IM can have:
- 30.000 primary logs (logs collecting from Basic History)
- 20.000 secondary logs (logs collecting from IM primary logs)
This means if you go for max on primary logs, not all of them can have a secondary log - which sounds kind of odd to me, but is perhaps what has been benchmarked in release tests?
The hierarchy you suggested seem to give 2 secondary IM logs for every primary IM log.
10.000 primary logs => 20.000 secondary logs.
30.000 primary logs => 60.000 secondary logs.
There are more IM experts on this forum; I'm not 100% sure 30.000 primary logs cannot be topped up with 30.000 secondary, on top (or even more if the hierarchy is "taller & wider"). Hopefully someone can fill in here?
Any moderate to large IM configuration need to be properly tuned with Sample Blocking Rate and a Stagger Value (see hsdbmaint.exe -stagger) to avoid sending down all requests in very large chunks to Basic History. Staggering means shredding them into smaller blocks/pieces and even the load put on the OPC HDA server of Basic History.