This is weird one. A particular index is generating duplicate documents every now and again. We can't consistently reproduce it, we just know it happens and that rebuilding the indexes manually fixes it.
The particularities of this project are (and may not mean anything):
- They are using load balancing (it's Winnebago)
- It does not happen in any of their qa and staging environments (not supported by load balancing)
- We have DoNotFailOnMismatchingCount set to true because we were having errors with it set to false
- We have some odd errors in the Event Viewer
- This is happening with our User's index only
- We're indexing Dealers and using this Repo in a Find a Dealer
(there's an IndexBuilderExtender and BeforeQuery Notification but I don't see how that would affect it in any way, since the problem is duplicate index documents)
The customer ends up having to manually rebuild the index, and because there's no explicit error, I don't have any logs to look into.
Can anyone think of a way I can get more info? This has been going on for months as we've been trying different approaches to reproduce the problem consistently.