10 months ago
We are migrating our service from Fly.io to Railway for better reliability.
Our backend is a proxy for multiple LLMs, built with Bun, Hono, and tRPC (specifically using httpBatchStreamLink; https://trpc.io/docs/client/links/httpBatchStreamLink).
We've discovered an issue where streams to our client apps are unexpectedly closing. This problem only occurs on our Railway deployment; the exact same code works perfectly on Fly.io.
We're eager to complete this migration. Are there any known issues, platform-specific configurations, or workarounds for this kind of streaming setup on Railway? We can provide a minimal reproducible repository (without LLMs) if needed.
Note that we disabled Serveless on the experiment while we enabled it now.
Please see the error log below:
[12:43:29.722] ERROR: onError(tRPC): {"error":{"cause":{},"code":"BAD_REQUEST","name":"TRPCError"},"path":"chatStream","ctx":{"req":{},"env":{}},"type":"mutation","req":{}}
{
error: 31 | var TRPCError = class extends Error {
32 | constructor(opts) {
33 | var _ref, _opts$message, _this$cause;
34 | const cause = getCauseFromUnknown(opts.cause);
35 | const message = (_ref = (_opts$message = opts.message) !== null && _opts$message !== void 0 ? _opts$message : cause === null || cause === void 0 ? void 0 : cause.message) !== null && _ref !== void 0 ? _ref : opts.code;
36 | super(message, { cause });
^
TRPCError: The connection was closed.
cause: [DOMException ...],
code: "BAD_REQUEST"
at new TRPCError (/app/node_modules/@trpc/server/dist/tracked-Bp72jHif.mjs:36:3)
at <anonymous> (/app/node_modules/@trpc/server/dist/resolveResponse-Hga1xOO1.mjs:53:11)
,
path: "chatStream",
input: undefined,
ctx: {
req: Request (0 KB) {
method: "POST",
url: "http://XXXXXX/api/trpc/chatStream?batch=1",
headers: Headers {
"host": "XXXXXX",
"user-agent": "Bun/1.2.20",
"content-length": "54604",
"accept": "*/*",
"accept-encoding": "gzip, deflate, br, zstd",
"content-type": "application/json",
"trpc-accept": "application/jsonl",
"x-forwarded-for": "XXXXXX",
"x-forwarded-host": "XXXXXX",
"x-forwarded-proto": "https",
"x-railway-edge": "railway/asia-southeast1-eqsg3a",
"x-railway-request-id": "PkHMtCQNTIK8wzXOacI7Nw",
"x-real-ip": "XXXXXX",
"x-request-start": "1755661470147",
}
},
env: HTTPServer {
address: [Object ...],
development: false,
fetch: [Function: fetch],
hostname: "0.0.0.0",
id: "",
pendingRequests: 0,
pendingWebSockets: 0,
port: 8080,
protocol: "http",
publish: [Function: publish],
ref: [Function: ref],
reload: [Function: reload],
requestIP: [Function: requestIP],
stop: [Function: stop],
subscriberCount: [Function: subscriberCount],
timeout: [Function: timeout],
unref: [Function: unref],
upgrade: [Function: upgrade],
url: [URL ...],
[Symbol(Symbol.dispose)]: [Function: dispose],
},
},
type: "mutation",
req: Request (0 KB) {
method: "POST",
url: "http://XXXXXX/api/trpc/chatStream?batch=1",
headers: Headers {
"host": "XXXXXX",
"user-agent": "Bun/1.2.20",
"content-length": "54604",
"accept": "*/*",
"accept-encoding": "gzip, deflate, br, zstd",
"content-type": "application/json",
"trpc-accept": "application/jsonl",
"x-forwarded-for": "XXXXXX",
"x-forwarded-host": "XXXXXX",
"x-forwarded-proto": "https",
"x-railway-edge": "railway/asia-southeast1-eqsg3a",
"x-railway-request-id": "PkHMtCQNTIK8wzXOacI7Nw",
"x-real-ip": "XXXXXX",
"x-request-start": "1755661470147",
}
},
}8 Replies
10 months ago
How long would you say the stream terminates after, we have a 15 minute websocket timeout for Railway generated domains.
Status changed to Awaiting User Response Railway • 10 months ago
10 months ago
Okay, it seems to be exceeding the 15-minute limit. We'll measure the exact duration to confirm. If we set up a custom domain, will that remove the 15-minute limitation?
Status changed to Awaiting Railway Response Railway • 10 months ago
10 months ago
Hmm, but, https://trpc.io/docs/client/links/httpBatchStreamLink seems not to use Websocket.
exkazuu
Okay, it seems to be exceeding the 15-minute limit. We'll measure the exact duration to confirm. If we set up a custom domain, will that remove the 15-minute limitation?
10 months ago
Yes.
Status changed to Awaiting User Response Railway • 10 months ago
10 months ago
Great! Anyway, We'll test our server with a custom domain and report the result.
Status changed to Awaiting Railway Response Railway • 10 months ago
10 months ago
I have just been informed that the limit isn't a WS specific throttle. Can you walk us through how long the connection lasts?
Status changed to Awaiting User Response Railway • 10 months ago
angelo-railway
I have just been informed that the limit isn't a WS specific throttle. Can you walk us through how long the connection lasts?
10 months ago
Okay. We cannot analyze the durations from the current logs. We'll improve our logger to measure the durations. Btw, I noticed that the error occurs both on non-streaming and streaming.
Status changed to Awaiting Railway Response Railway • 10 months ago
10 months ago
Yea, from the network request on our side we got a 200.
From the engineering team: "The request ID they gave was for a POST request that returned a 200 in 20 ms with ~50kb, so all is good on our end."
Status changed to Awaiting User Response Railway • 10 months ago
9 months ago
This thread has been marked as solved automatically due to a lack of recent activity. Please re-open this thread or create a new one if you require further assistance. Thank you!
Status changed to Solved Railway • 9 months ago