10 hours ago
Hi Railway team,
I'm a Pro customer building a real time application that uses Server Sent Events (SSE) to stream long running task progress to clients. Application state lives in memory on the instance that started the task.
I'm approaching a point where I need to add a second replica for capacity and zero downtime deploys. The blocker is that Railway's load balancer randomly distributes requests across replicas, so a client's SSE reconnect can land on an instance that doesn't own its task, breaking the stream.
The standard solution is cookie based session affinity at the load balancer. Other platforms in your peer set (Render, Fly.io, DigitalOcean App Platform, AWS ALB, Cloudflare LB) all support this out of the box. There's been an open feature request for this on Help Station without movement: https://station.railway.com/feedback/sticky-sessions-fa65efc4
Without sticky sessions migrate to a provider that supports session affinity natively.
A few questions:
Is sticky session / session affinity on the roadmap? Any rough timeline?
If not, is there a Railway recommended pattern for SSE/WebSocket apps that need replica affinity, beyond the Help Station Redis suggestion?
Would a Pro customer's migration over this issue factor into prioritization?
Happy to chat live if it's useful. I'd much rather stay on Railway, the dashboard and developer experience are best in class, but I can't ignore an architectural blocker.
Thanks,
Grigor
AIQuorum Inc.
5 Replies
10 hours ago
We do not currently support sticky sessions, and there is no timeline to share on when it might be available. Our docs explicitly note this as a current limitation of horizontal scaling. For SSE or WebSocket apps that need replica affinity, the recommended approach is to externalize your task state (e.g., into Redis or a database) so any replica can serve any client's reconnect, rather than relying on load-balancer affinity. Regarding live calls, those are available only on our Enterprise plan if that's of interest.
Status changed to Awaiting User Response Railway • about 10 hours ago
Railway
We do not currently support sticky sessions, and there is no timeline to share on when it might be available. Our docs explicitly note this as a current limitation of horizontal scaling. For SSE or WebSocket apps that need replica affinity, the recommended approach is to externalize your task state (e.g., into Redis or a database) so any replica can serve any client's reconnect, rather than relying on load-balancer affinity. Regarding live calls, those are available only on our [Enterprise plan](https://cal.com/team/railway/work-with-railway) if that's of interest.
9 hours ago
Thanks, but the AI response just restated what's in your public docs and didn't address my actual questions. I already know Redis pub/sub is the workaround, that's exactly the rewrite I want to avoid by staying on Railway.
Could a human from the platform team weigh in on:
Is sticky session / session affinity actually on the roadmap, or is "no timeline" code for "not planned"? An honest answer either way helps me make a decision.
If a Pro customer is going to migrate over a missing platform feature, is that something the team factors into prioritization, or no?
I'd rather stay on Railway than rewrite my event-delivery layer or move providers. But I can't justify either of those without knowing whether the platform is going to close this gap.
Status changed to Awaiting Railway Response Railway • about 9 hours ago
9 hours ago
Sticky sessions are not currently on a published roadmap, and we don't have an internal timeline to share. That's a straightforward "not planned right now" rather than a diplomatic dodge. Feature requests on Help Station do factor into prioritization, and upvotes plus concrete use cases from paying customers carry weight, but we can't make commitments on if or when it ships.
Status changed to Awaiting User Response Railway • about 9 hours ago
Railway
Sticky sessions are not currently on a published roadmap, and we don't have an internal timeline to share. That's a straightforward "not planned right now" rather than a diplomatic dodge. Feature requests on [Help Station](https://station.railway.com/feedback/sticky-sessions) do factor into prioritization, and upvotes plus concrete use cases from paying customers carry weight, but we can't make commitments on if or when it ships.
9 hours ago
Understood. Going to migrate to a platform with native session affinity. Would love to come back if Railway adds it down the road.
Status changed to Awaiting Railway Response Railway • about 5 hours ago
an hour ago
Completely fair. We'll note this as a concrete churn case on the sticky sessions feature request. If it ships, we'll make noise about it - hope to have you consider coming back then!
Status changed to Awaiting User Response Railway • about 1 hour ago
Status changed to Solved chandrika • about 1 hour ago