Delivered Append-Only Index Feature Documentation for OpenSearch in the documentation site (opensearch-project/documentation-website). The documentation covers the Append-Only Index concept (immutable indices that only accept document ingestion), the benefits (data integrity, auditability, simplified ingestion pipelines), and the creation process. Updated index settings docs to include the new append-only setting and related configuration guidance. The work is anchored by commit 0e388a7a60a3ba78c29a73249b6e06e25e299021 (Adding documentation for append only indices (#9809)). This deliverable enhances developer onboarding, reduces support friction, and aligns product capabilities with accessible, up-to-date documentation.

January 2025 monthly summary for wazuh-indexer: Delivered an important feature set around append-only indices to enhance data integrity and auditability. Implemented append-only indices support with a retry-based path that creates a new version instead of in-place updates, and enforced that updates are disallowed on append-only indices. This reduces risk of accidental mutations and strengthens versioned data retention. The work includes tests to verify update behavior for append-only indices, ensuring reliability and regression safety. No unrelated major bug fixes were reported this month; the focus was on feature delivery and quality assurance.