René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[horizontal scaling] How to actually build session persistence in streamable http MCP server?","articleBody":"I have a question here regarding how to build session persistence into an MCP server.\n\nI am running my mcp server (FastMCP) in an ecs service with multiple tasks. I have built a redis event store to allow for resumability. The service sits behind an ALB that directs HTTPS traffic to it. Inspite of all of it, Im still observing intermittent `Bad Request: No valid session ID provided` 400 errors when I connect the mcpinspector.\n\nMy suspicion is StreamableHTTPSessionManager doesn't seem to be able to store session-id data in an external data source. Therefore traffic from a client has to always hit the same task since the session id is tied to a server.\n\nIn an AWS architecture, how do I configure my server and client to accomplish this. Is using sticky sessions the only route here? Are streamable http sessions not horizontally scalable?","author":{"url":"https://github.com/karthich","@type":"Person","name":"karthich"},"datePublished":"2025-06-03T18:19:07.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":22},"url":"https://github.com/880/python-sdk/issues/880"}