Jaeger v2.20.0 introduces significant advancements in observability for modern workloads, led by deep integration for GenAI tracing and the adoption of Elasticsearch Data Streams. The release also overhauls the UI with native flamegraphs and improved trace summaries, while streamlining the backend by removing legacy Elasticsearch v6 support and consolidating extensions.

Drop support for Elasticsearch v6 — Users running older Elasticsearch v6 clusters must upgrade their storage backend to v7+ or OpenSearch before updating Jaeger, as support for the legacy v6 engine has been removed.

Enhanced GenAI Trace Visualization and Semantics — Developers working with LLM-based applications can now easily distinguish and analyze AI-specific behaviors (like retrieval, tool calls, and agent reasoning) thanks to dedicated UI icons, specialized attribute rendering, and a new GenAI-focused timeline viewer.

Elasticsearch Data Streams Support — Ops teams can now utilize Elasticsearch/OpenSearch Data Streams for span storage, providing a more modern and scalable way to manage high-volume time-series data compared to traditional index rotation.

Native Flamegraph Trace View and UI Enhancements — Users get a powerful new way to visualize complex traces with a native, resizable flamegraph view, making it easier to identify performance bottlenecks and service execution patterns at a glance.

MCP Consolidation and Beta Storage Gate Promotion — Administrators using the Jaeger MCP (Model Context Protocol) must update their configurations as the extension has been merged into the standard jaegerquery extension. Additionally, Elasticsearch rotation and index-cleaner features are now promoted to beta with a new configuration schema.