Yoann Rodière ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *closed* an issue as *Rejected* I had a closer look, and it seems this feature is only effective if the MergePolicy implement findFullFlushMerges. None of the built-in merge policies do, and in particular the (non-configurable) merge policy defined by Hibernate Search doesn't. So, this setting is currently pointless, at least until we allow users to provide their own MergePolicy. Closing this for now. See org.apache.lucene.index.IndexWriterConfig#DEFAULT_MAX_COMMIT_MERGE_WAIT_MILLIS Hibernate Search ( https://hibernate.atlassian.net/browse/HSEARCH?atlOrigin=eyJpIjoiNmNlNTg1... ) / Improvement ( https://hibernate.atlassian.net/browse/HSEARCH-3966?atlOrigin=eyJpIjoiNmN... ) HSEARCH-3966 ( https://hibernate.atlassian.net/browse/HSEARCH-3966?atlOrigin=eyJpIjoiNmN... ) Configuration properties for merge-on-commit with Lucene 8.6 ( https://hibernate.atlassian.net/browse/HSEARCH-3966?atlOrigin=eyJpIjoiNmN... ) Change By: Yoann Rodière ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) Fix versions: 6.0.0.Beta-backlog Resolution: Rejected Status: In Progress Closed ( https://hibernate.atlassian.net/browse/HSEARCH-3966#add-comment?atlOrigin... ) Add Comment ( https://hibernate.atlassian.net/browse/HSEARCH-3966#add-comment?atlOrigin... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100140- sha1:fbb0377 )