OPC DA Server should periodically update its cache from the PI Server after the initial start
The OPC DA Server service uses %PIPC%\PI_OPCDA2\Data\SavedNamespace.xml to load the tags and does not update the cache until the service is stopped and started again. If any new tag is added to the PI Server, it is not picked by the OPC DA Server. The service should periodically update its cache from the PI Server after the initial start.
We also faced the same issue recently. We removed the content from SavedNamespace to resolve it. However, we should have some configuration like "Disconnected Startup" where we can specify the frequency of time to sync the tag list to the SavedNamespace cache file. It should handle add/modify/deletion of PI Server tags.
The problem we are currently trying to solve has to do with changes made while the PI OPC DA Server is down. We find out about new PI points when we restart but we miss PI point edits and deletions. In PI OPC DA Server 2018, we will start validating the cached namespace against the PI Data Archive as a low-priority task after startup. I am wondering how periodic writes to a namespace cache file while running would be helpful.