A few weeks back I was working on a PoC with Bedrock AgentCore Runtime. While doing that I came across multiple blogs and discussions around MCP server hosting on AWS. Most of them were pointing to either Bedrock AgentCore or Lambda. Very few talked about ECS Fargate. That got me thinking. I have been using Fargate for containerised workloads for a while now. It is my go-to when a team needs containers without managing the underlying infrastructure. So the question came naturally — can Fargate host a stateful MCP server? And more importantly, what happens when you actually deploy it in a real scenario? As an architect I believe you should know all the options before recommending one. Not just what the docs say — what actually happens when you run it. So I decided to test it myself. This blog is what I found. Specifically what happens when you run a stateful MCP server on ECS Fargate and then do a rolling deployment while a session is active. The results were not what I expected.…