- order now stage 3 -> 22 -> 31 -> 24 -> 23: correctness before measurement (multi-shard DB traps WO_T_DB today) - stories 08/11 catch up to landed arc stages 1+2 (plan of record, deviations, settled open questions) - 22 gains multi-shard + mutex-inbox targets; deltas owed retroactively - 23 rides arc's per-shard ring (T4); old-id order string superseded - 24 depends on 31; 19 landed so Bytes ready - new story: refine/31-actor-lifecycle.md (request/response, bounded mailboxes, death/supervision, timers) - 00-story table + 00-status pending resequenced; held rows link hold/; ids stay immutable, no renames Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
79 lines
3.9 KiB
Markdown
79 lines
3.9 KiB
Markdown
# Iteration 24 — chat: the WebSocket pub/sub driving workload
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> Format: fiberloom `product/story-iteration-template`. Part of
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> [Story — one language, one runtime, one database, one binary](../00-story.md).
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>
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> **Inserted 2026-08-20** (concurrency-chain refinement): the 8+11 arc's
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> driving workload, the role log-watcher played for iterations 3–7. Needs
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> its spec AFTER the arc's — it lands at the arc's end and proves it.
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>
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> **RE-SEQUENCED 2026-08-21**: fourth in the chain,
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> **stage 3 → 22 → 31 → 24 → 23** — chat cannot be written honestly
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> before [iteration 31](31-actor-lifecycle.md) (request/response,
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> bounded mailboxes, actor death, timers). Iteration 19 LANDED
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> 2026-08-20, so Bytes is available for frame parse/serialize.
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## Why this iteration exists
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Everything the framework ledger parks behind concurrency — WebSockets,
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pub/sub, streaming, per-request cancellation, the keep-alive parking
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retirement — needs a workload that actually exercises long-lived
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connections and cross-shard broadcast, or the arc ships mechanism without
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proof. Chat is the smallest honest such workload: rooms, N concurrent
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clients, fan-out on every message, presence on connect/disconnect — one
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binary, no broker.
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## Goals
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- `docs/examples/chat`: rooms + broadcast + presence over WebSocket,
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served by the framework through `[deps]` exactly as the web-app is.
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- Framework grows the WS mechanism in pure `.wo`: the HTTP/1.1 upgrade
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handshake (Sec-WebSocket-Accept needs SHA-1/base64 — the crypto-builtin
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fork's first real consumer), frame parse/serialize (text, close, ping),
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fiber-per-connection serving (iteration 11), and in-memory channels
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whose delivery is cross-shard message send (iteration 8).
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- The arc's acceptance teeth: 1k concurrent clients across shards,
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broadcast latency measured, starvation-free under one hot room,
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SIGTERM drains every connection cleanly.
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## Acceptance Criteria (draft — the spec after the arc refines)
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- **Given** two clients in one room on DIFFERENT shards, **when** one
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sends, **then** the other receives the frame (cross-shard ownership-move
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delivery), and a third client in another room receives nothing.
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- **Given** 1k connected clients with one hot sender, **when** the
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reduction budget preempts, **then** every room keeps making progress
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(no starvation) on one OS thread per core, verified by TID.
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- **Given** SIGTERM with clients connected, **when** the server drains,
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**then** every connection gets a close frame, every fiber unwinds its
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drop maps (ASan zero leaks), and the process exits 0.
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- **Given** the web-app running beside chat features, **when** the
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standing gates run, **then** nothing regresses — HTTP and WS share the
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serve loop honestly.
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## Out Of Scope
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Message persistence/history (a `@table` an app adds if it wants — not the
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workload's point); auth beyond the existing bearer mechanism; permessage
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compression; binary frames beyond echo coverage; wss (TLS stays at the
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proxy — the proxy story extends to WS pass-through, documented).
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## Info
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- Dependencies: the 8+11 arc (fibers + cross-shard send — stages 1+2
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landed 2026-08-20, stage 3 pending), [iteration 31](31-actor-lifecycle.md)
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(request/response, backpressure, death, timers — the mechanisms rooms
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and presence are made of), iteration 19 (LANDED 2026-08-20 — Bytes
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carries the frames), the crypto builtins fork (SHA-1 for the upgrade
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handshake — note: the ledger's crypto slice lists SHA-256/512; the WS
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handshake specifically needs SHA-1, so the builtin set must include
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it), and the framework's parse seam (upgrade is an HTTP request until
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it isn't).
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- Unparks on landing: the framework ledger's WebSocket/pub-sub rows and
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the iteration-18 rejection note ("pub/sub REJECTED until 8/11").
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## Proposed Solution
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Brainstorm → spec → plan after the arc's spec exists; the arc's plan and
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this iteration's are written against each other (the arc names chat as
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its acceptance, chat names the arc as its substrate).
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