Migrating to 7.12

Migrating to 7.12

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 7.17 and Release notes.

Breaking changes

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 changes

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 changes

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.

SSL/TLS changes

TLSv1.1 and TLSv1.0 are disabled in the bundled JDK

Details
As of Elasticsearch 7.12.1, when using the bundled JDK, TLSv1.1 and TLSv1.0 are disabled by default. This may affect SSL connections to the Rest API for some older clients. It also has the potential to affect outgoing connections such as Watcher webhooks, LDAP authentication or access to snapshot repositories.

Most Elasticsearch deployments will not be affected by this change, as these older TLS versions have known vulnerabilities and are no longer heavily used.

For instructions on how to enable these older TLS versions in your Elasticsearch cluster, see Enabling additional SSL/TLS versions on your JDK.

Deprecations

The following functionality has been deprecated in Elasticsearch 7.12 and will be removed in 8.0 While this won’t have an immediate impact on your applications, we strongly encourage you take the described steps to update your code after upgrading to 7.12.

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.

Settings deprecations

Setting xpack.searchable.snapshot.shared_cache.size on non-frozen nodes is deprecated.

Details
Setting xpack.searchable.snapshot.shared_cache.size to a positive value on a node without the data_frozen role is now deprecated.

The xpack.searchable.snapshot.shared_cache.size node setting reserves space for a shared cache used by partially mounted searchable snapshot indices. Elasticsearch only allocates partially mounted indices to nodes with the data_frozen role.

Impact
To avoid deprecation warnings, discontinue use of the setting on non-frozen nodes.