_forcemerge query not working? (from Elastic Cloud - ES 2.1.1)

Continuing the discussion from _forcemerge query not working?:

This is a very specific elasticsearch-centric question; I've reposted this in the appropriate topic.

The issue in question is around Elasticsearch 2.1.1.

Hmm there was this bug in Lucene:


where Lucene failed to trigger merges if all you did was delete and never add any documents, but it was fixed in Lucene 5.3.0 and should be included in ES 2.1.1, so you should have seen merges running without having asked for forceMerge. Have you added any documents since doing the deletions?

Are you sure there are no merges running? They will take quite some time to complete. What refresh_interval do you have?

Separately, forceMerge definitely should have done something.

Can you post any settings you've changed from defaults?