800xA Event List takes much time to display
When I clicked on Show Events icon from Web System Workplace:Alarm List to display the event view, this takes much time to display: about 15 seconds.
The customer said me that the view is displayed in 2 seconds.
I checked all services are good for OPC DA Server and OPC AE Server.
What is the problem ?
the version of 800xA is sv5.1 RevC
Thank you for your help .
Voted best answer
Problem is resolved and I said thank you.
I decreased the value of Storage Classes per Harmony alarm & event categories
from 100.000 to the default value 10.000
I let the scheduling disk defragmenter for monthly.
The display of event view takes now 7 seconds instead of 25 seconds.
The 7 seconds is normal because the alarm attribute area is used to filter alarms and events.
Thanks a lot.
If you are already displaying an Alarm List and you click on the "Show Events" icon for that alarm list then YES, it does take a while.
This is normal. The Alarm List must search for all the events that are supposed to be filtered into the list, and that search takes many seconds.
Roughly 10.000 alarms are stored in RAM of the Alarm Manager service.
Events are much larger in number and stored persistently on disk by the Event Storage service.
Disk access is much slower than memory access. Additionally the storage method is unfortunately *not* SQL, etc. All filtering causes "full table scans" of text/strings.
1. Ensure that filtering is as little as possible
2. Ensure that sorting is as simple as possible (eg EventTime, descending)
3. Ensure Event Storage service storage parameters are default or increased only within "sane" limits (eg up to 50.000) events per category. Performance drop is linear to number of events that need to be filtered.