Add ElasticsearchIO External Versioning

Elasticsearch External Versioning

Beam's ElasticsearchIO Java SDK currently does not support external versioning.

Use Case

A primary use case is leveraging partial updates when performing a reindex operation. Without explicitly setting the external version, the versioning is set to default and version conflicts prevent any document updates.

API Usage for External Versioning

When using Elasticsearch's API, the ?version_type=external&version=1.0.0 query parameters must be provided.

The options for version_type are:

• external or external_gt
• external_gte