Upgrade Jackson 2 to Jackson 3 in sdk/cosmos

[rujche]

Summary

Upgrade Jackson from major version 2 (com.fasterxml.jackson) to major version 3 (tools.jackson) across all modules under sdk/cosmos.

Context

As part of aligning with Spring Boot 4, the sdk/spring modules were migrated from Jackson 2 to Jackson 3 (see #49538 and #49550). During that work, the Cosmos modules (azure-spring-data-cosmos and, transitively, azure-cosmos) were intentionally left out of scope because they cannot be migrated in isolation.

This issue tracks the follow-up work to bring sdk/cosmos to Jackson 3 so that azure-spring-data-cosmos and the Spring Cloud Azure Cosmos starter can fully move off Jackson 2.

Why Cosmos could not be upgraded together with sdk/spring

azure-cosmos exposes Jackson 2 types as part of its public API, not just internally. Around 65 public (non-implementation) classes import com.fasterxml.jackson, for example:

• CosmosItemSerializer (public abstract extension point whose signatures use ObjectNode / JsonNode)
• CosmosItemResponse, CosmosBulkItemResponse, CosmosBatchOperationResult
• Most com.azure.cosmos.models.* properties classes (CosmosContainerProperties, IndexingPolicy, SqlQuerySpec, ...)

Because JsonNode is part of the public contract, switching to Jackson 3 is a breaking API change for azure-cosmos. That change cascades to every module that depends on it.

Affected modules

Modules under sdk/cosmos that depend on azure-cosmos and/or use Jackson 2 directly (approximate Jackson 2 file counts):

Module	Jackson 2 files
azure-cosmos	221
azure-cosmos-tests	103
azure-cosmos-spark_3 (+ all spark variants)	52+
azure-cosmos-kafka-connect	20
azure-cosmos-encryption	14
azure-cosmos-benchmark	9
azure-cosmos-test	—

Roughly 440+ source files reference Jackson 2 across the tree.

Considerations

• azure-cosmos is a GA data-plane library; a 2 -> 3 migration that changes the public API is a breaking change and requires the appropriate API review / approval.
• Options to evaluate:
  • Additive Jackson 3 support in azure-cosmos (keep the Jackson 2 public API, add Jackson 3) to avoid an immediate break for downstream consumers.
  • A full migration across all sdk/cosmos modules in lockstep.
• The Jackson 2 annotations namespace (com.fasterxml.jackson.annotation) is unchanged in Jackson 3 and can be retained.

Related

• Use Jackson 3 in Spring Cloud Azure 7.x to align with Spring Boot 4 #49538
• Upgrade sdk/spring to Jackson 3 to align with Spring Boot 4 #49550

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @kushagraThapar @pjohari-ms @TheovanKraay.