Segments with 60-70% deleted docs (5G) never remove deleted docs

Will a 5g segment ever be selected for merging? We have 5g segments with up to 60-70% deleted docs. We have been monitoring and the segments never appear to be selected for merge.

Any segment should be a potential for merging. Have you tried a force merge?

The issue we were having with force merge was that we were ending up with very large segment sizes (30G). This would cause issues with rebalancing as the shards would bounce around looking for a node to land on. The command run was: _forcemerge?only_expunge_deletes=true. Are there additional flags that should be used to limit the segment size to 5g? Thanks much.