Description

Read sessions following live updates (i.e., caught up to the stream tail with wait=∞) are terminated with StreamerMissingInActionError (503 Unavailable) after 60 seconds of no appends to the stream. This contradicts the documented behavior that unbounded sessions will "follow in real-time for new records" indefinitely.

Reproduce

1. Create a stream and append some records
2. Start a read session with no bounds (default wait=∞) — e.g., via SSE or SDK readSession( { start: { seqNum: 0 }, } (according to the docs, this should be a session without bounds: https://s2.dev/docs/api/records/read#follow-live-updates)
3. Wait 60+ seconds without appending any records
4. Observe the read session terminate with:

   S2Error: {"code":"unavailable","message":"streamer missing in action"} (status 503)
   

Expected Behavior

An unbounded read session following live updates should remain open indefinitely (or until the client disconnects), as documented:

Once the stream tail is reached, sessions follow real-time for new records if no bounds apply or wait is non-zero.

Actual Behavior

The session is dropped after ~60 seconds of stream inactivity with a 503 Unavailable error.

Notes

This seems to be caused somewhere here: