We have custom web app which uses PI web API.
Also we have external MS SQL table lookup.
For a long time we have been seeing the changes in the external MS SQL table immediately when we clicked ok in the app (the code writes directly to MS SQL, but show data through PI Web api).
Since 1 week it's not the case anymore.
The data in MS SQL updates correctly and immediately, but in PI web API page I can see a irregular delay 30 sec, 2 min, 15 min, 2 hour.
We tried to restart all PI servers it didn't help.
Please advise what might be the reason and how we can investigate and solve this problem?