Realtime Broadcast: Buffer coalesces sequential messages
realtimeWe're sending broadcast messages with
We ran 3 identical tests changing only the server delay. Client processing delay was 0ms — measuring raw arrival via
Each game round has a setup phase (~12 events, 400-800ms apart) then a play phase (5 groups × 4 rapid sends). Only the play phase shows batching.
When messages DO flow, timing matches the server delay perfectly (~850ms gaps for 800ms, ~2s for 2000ms).
The pattern is consistent across 75+ groups: earlier groups in a round batch, later groups flow. Longer delays drain the buffer faster. At 500ms it never drains within 5 groups. At 2000ms it drains by group 2-3. The setup phase events always arrive individually.
Question: Is there a buffer in the Realtime delivery path (WebSocket layer, Phoenix Channels, Realtime server) that coalesces pending outbound messages? Can it be flushed or disabled?
Free tier, @supabase/supabase-js latest, Node.js server, broadcast only, single channel, all local. Happy to share full logs.
awaitchannel.send()We ran 3 identical tests changing only the server delay. Client processing delay was 0ms — measuring raw arrival via
Date.now()Each game round has a setup phase (~12 events, 400-800ms apart) then a play phase (5 groups × 4 rapid sends). Only the play phase shows batching.
When messages DO flow, timing matches the server delay perfectly (~850ms gaps for 800ms, ~2s for 2000ms).
The pattern is consistent across 75+ groups: earlier groups in a round batch, later groups flow. Longer delays drain the buffer faster. At 500ms it never drains within 5 groups. At 2000ms it drains by group 2-3. The setup phase events always arrive individually.
Question: Is there a buffer in the Realtime delivery path (WebSocket layer, Phoenix Channels, Realtime server) that coalesces pending outbound messages? Can it be flushed or disabled?
Free tier, @supabase/supabase-js latest, Node.js server, broadcast only, single channel, all local. Happy to share full logs.
