Hono•2mo ago

Hono SSE Stream Closing Unexpectedly After 10 Seconds

Title: Hono SSE Stream Closing After 10 Seconds Issue: Using Hono's streamSSE, the SSE connection closes after ~10 seconds, regardless of client (curl/browser). A minimal Node.js SSE server works fine. Environment: Debian, localhost Code snippet:

app.get("/render", (c: Context) => {
  return streamSSE(c, async (stream) => {
    while (true) {
      await stream.writeSSE({
        data: `It is ${new Date().toISOString()}`,
        event: "time-update",
      });
      await stream.sleep(1000);
    }
  });
});

app.get("/render", (c: Context) => {
  return streamSSE(c, async (stream) => {
    while (true) {
      await stream.writeSSE({
        data: `It is ${new Date().toISOString()}`,
        event: "time-update",
      });
      await stream.sleep(1000);
    }
  });
});

Logs show:

SSE connection initiated
Sending message #1: It is 2024-08-30T14:21:10.214Z
...
Sending message #9: It is 2024-08-30T14:21:18.236Z
Stream aborted by client

SSE connection initiated
Sending message #1: It is 2024-08-30T14:21:10.214Z
...
Sending message #9: It is 2024-08-30T14:21:18.236Z
Stream aborted by client

Any ideas why Hono's SSE implementation might be closing the connection prematurely? Tried error handling and abort detection, issue persists. Thanks for any help!

12 Replies

Aditya Mathur•2mo ago

Which runtime are you using? I tried with Nodejs, seems to be working for me

Chris•2mo ago

I am using bun as runtime Do you think this could be an issue?

Aditya Mathur•2mo ago

Maybe, try changing the runtime to nodejs for checking this 🧪 , and if the problem is resolved, try searching the bun docs or ask a question regarding this on their discord

ex0ns•2mo ago

https://discord.com/channels/1011308539819597844/1011308539819597847/1277621456586670203 I had this issue since version 1.1.26 of bun.... this is a nasty setting to change in a patch

Chris•2mo ago

Thank you so much! You saved us a lot of time. How did you solve this issue or better what do you reccomend to to? Should we just downgrade our version and wait till hono fixes their serve or is that something we need to configure by our own?

ex0ns•2mo ago

I increased the value of idleTimeout

export default {
  port: process.env.PORT ?? 8787,
  fetch: app.fetch,
  idleTimeout: 0,
};

export default {
  port: process.env.PORT ?? 8787,
  fetch: app.fetch,
  idleTimeout: 0,
};

Chris•2mo ago

Is setting the idleTimeout: 0, the same as setting it to inf? Or would you reccomend using a real value and actually making use of the feature

ex0ns•2mo ago

Yes it is. But I only use bun to dev, in prod we use node.js so this value is only use locally, but I agree that you should probably set it to another value if you use bun in production

Chris•2mo ago

Are there any reasons for your prof/dev setup? Did you choose node.js for prod because of stability? We're running bun in both dev and prod but often debate if node is a more mature and stable option. So far bun did a good job but more recently we are facing more and more issues

ex0ns•2mo ago

Honestly, I just node.js because I'm more familiar with it and was easier for me to work with Node.js, however due to some monorepo, bundling and typescript setup running our server locally on our laptop became a pain in the a** (tsx, ts-run, you name it always failed at some point), I decided to try bun to run TS natively and it worked amazingly so far.

BridgeSense•2mo ago

thanks so much for this, just spent a few hours trying to fix it

IvanCN•2mo ago

Fixed: Default idleTimeout no longer set in node:http In Bun 1.1.26, the default idleTimeout was 10 seconds, which was a breaking change as versions before had unlimited timeout. The default value of idleTimeout is now 0, which disables the timeout.

https://bun.sh/blog/bun-v1.1.27#fixed-default-idletimeout-no-longer-set-in-node-http

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Fixes 130 bugs (addressing 250 👍). bun pm pack, faster node:zlib. Static routes in Bun.serve(). ReadableStream support in response.clone() & request.clone(). Per-request timeouts. Cancel method in ReadableStream is called. bun run handles CTRL + C better. Faster buffered streams. bun outdated package filtering. Watch arbtirary file types...

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Hono SSE Stream Closing Unexpectedly After 10 Seconds