Migrating to 7.12edit

This section discusses the changes that you need to be aware of when migrating your application to Elasticsearch 7.12.

See also What’s new in 7.12 and Release notes.

Breaking changesedit

The following changes in Elasticsearch 7.12 might affect your applications and prevent them from operating normally. Before upgrading to 7.12, review these changes and take the described steps to mitigate the impact.

Breaking changes introduced in minor versions are normally limited to security and bug fixes. Significant changes in behavior are deprecated in a minor release and the old behavior is supported until the next major release. To find out if you are using any deprecated functionality, enable deprecation logging.

Engine changesedit

Force-merges on frozen and searchable snapshot indices will fail if merging is required.

Details
In earlier versions a force-merge on a frozen index or a searchable snapshot index would incorrectly yield a successful response without performing the requested merge. This bug is fixed in version 7.12: from this version onwards a force-merge on these immutable indices will fail if the requested merge is not a no-op.

Search changesedit

The search APIs fields parameter returns fields inside nested fields grouped together.

Details
In earlier versions, fields retrieved via fields in the search API were returned as a flat list. From 7.12 on, fields inside an object that is mapped using the nested field type are grouped together to maintain the independence of each object inside the original nested array.