OpenSearch 3.8 brings faster vector ingestion via Base64 encoding (up to 4.16x throughput gain), a redesigned radial search algorithm delivering 2.1x higher query throughput and better recall, and expanded MCP support across all four agent types. LLM-as-a-Judge now works with any ML Commons connector instead of just OpenAI, and ML Commons streaming inference gains gRPC transport for lower latency. Observability gets a visual PPL query builder, SQL support in Discover logs, an onboarding canvas, new PPL commands (makeresults, foreach, xyseries, timewrap), a PPL lint engine, a Grok Debugger, and one-click alert creation from Prometheus metric exploration. Amazon Linux 2 support is being deprecated as a CI build image and supported OS in a future version.
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Search modernizationObservability and analyticsInfrastructure updatesGetting startedAuthorQuestions this post answers
How much faster is vector ingestion in OpenSearch 3.8 with Base64 encoding?
OpenSearch 3.8 delivers up to 4.16x higher bulk vector ingestion throughput using Base64-encoded knn_vector fields, with 83% lower median latency. A 768-dimensional float vector shrinks from about 16 KB as a JSON array to 4 KB in Base64, cutting network payload by 74%. It works transparently across all supported k-NN engines with no mapping changes required. Teams tuning vector search pipelines can track performance-focused releases like this one on daily.dev.
Does OpenSearch 3.8 support MCP for all agent types?
Yes, OpenSearch 3.8 extends Model Context Protocol support to flow and conversational flow agents, meaning all four agent types (conversational, plan-execute-reflect, flow, and conversational flow) can now connect to external MCP-compliant tool servers using a consistent connector configuration. Previously only conversational and plan-execute-reflect agents supported MCP integrations. Engineers building agentic search workflows can follow MCP integration updates like this on daily.dev.
When is Amazon Linux 2 support being deprecated in OpenSearch?
OpenSearch will deprecate support for Amazon Linux 2 as a continuous integration build image and supported operating system in a future version, though no exact version was specified. Amazon Linux 2 itself reached end of support from AWS on June 30, 2026, prompting the change. Ops teams planning OS migrations can watch for deprecation timelines like this on daily.dev.