Hi @stevie-sy, @log1c - thanks both for the replies.
I’ve changed to replace (that probably makes more sense for what I was trying to do!). I’ve also done some manual tidy up.
It would seem to me that merge+purge doesn’t remove anything; I thought it might merge data in the records, but deleting missing - which probably doesn’t make much sense. I wonder if ‘purge’ should only work with ‘replace’.
The other issue I seemed to be hitting is - for things where i’d already removed a few weeks ago from the config file and done a sync with purge set to false - those were left on the system. Presumably as they had already been removed from director; and so it didn’t recognise the record in icinga as something it could purge.
For my particular use case, where i’m trying to use director and a defined json file to populate the hosts, running with replace+purge probably makes most sense.
In any case, thanks for the pointers guys and I’ve resolved the issue with your assistance