Edge Historian Not Storing Every Change
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I am attempting to analyze tag history at the edge for MQTT Engine tags to confirm peer to peer communications between edge nodes are operating as expected. I noticed large numbers of tag history entries missing from the Edge as compared to our central Ignition gateway and went down a bit of a rabbit hole with checking packet loss, TCP dumps etc... I then began querying the tag historian in the edge to see what was being stored, I noticed that as I queried, tags would be stored but then later removed as new values came in and I could see that the messages were being received by Engine consistently. Is this the intended functionality of the edge historian? Am I missing something? The tag history is configured as follows:
With identical settings for the same tag in the central gateway which has no loss in the historian.
Note: this tag changes every minute and there are only 6 tags in engine which are being used for this test.
Both Edge and Central are using Ignition 8.1.9