- gateway-metrics: collectors now run per scrape so Prometheus sees real data (process memory/uptime + live AI-analysis pipeline gauges) instead of an always-empty stub. bootstrap registers the pipeline collectors. - systemd: MemoryMax 512M -> 1G (live RSS ~500MiB, peak 508MiB; 512M left ~2% headroom and risked an OOM-kill restart; host has 8GB free). - config: POSTGRES_POOL_MIN 2 -> 0 so main + 4 Piscina worker threads don't hold ~10 permanently-open idle pg connections against PgBouncer. - docs: rewrite stale ARCHITECTURE.md / MODULE_STRUCTURE.md (winston -> pino, removed mock-crc/indonesianTextNormalizer, renamed aiAnalysisWorker/llmModerationClient). Verified: tsc clean, 129 vitest pass, biome clean on changed files. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
144 lines
7.6 KiB
Markdown
144 lines
7.6 KiB
Markdown
# Discord Gateway — Architecture
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Pure event-driven microservice (no HTTP server). Captures Discord
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messages/voice/attachments/reactions/threads/presence, runs LLM-based AI
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moderation, and publishes everything to Redis pub/sub for the backend to
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consume. The backend serves the HTTP/WS API to the frontend.
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> NOTE: this doc is the source of truth for the module layout. The older
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> `MODULE_STRUCTURE.md` was stale (referenced `winston`, `mock-crc.ts`,
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> `indonesianTextNormalizer.ts`, and `aiAnalysisWorker.ts`/`llmModerationClient.ts`
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> which were renamed/merged). If they disagree, this file wins.
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## Top-level layout
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```
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services/discord-gateway/
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├── src/
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│ ├── index.ts # Entry point → initializeDiscordGateway()
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│ ├── app/
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│ │ ├── bootstrap.ts # Wires client, DB, Redis, workers, schedulers
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│ │ ├── shutdown.ts # Graceful shutdown (SIGINT/SIGTERM + transient errors)
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│ │ └── retention.ts # Expired-record cleanup scheduler
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│ ├── shared/
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│ │ ├── config/ # Zod-validated env (index.ts = schema+loader)
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│ │ ├── database/ # Drizzle ORM + pg Pool + migrations
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│ │ │ ├── init.ts drizzle.ts pool.ts migrate.ts migrateCli.ts
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│ │ │ └── schema/ # messages, cache, voice, analytics, meta
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│ │ ├── logger/ # pino wrapper + createChildLogger()
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│ │ ├── errors/ # AppError / ConfigError / AudioError ...
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│ │ ├── utils/ # retry, pagination
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│ │ ├── discord/clientOptions.ts # discord.js-selfbot-v13 client options
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│ │ ├── uploader.ts # Shared attachment upload helper
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│ │ ├── redis-channels.ts # Redis channel-name constants
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│ │ └── moderation-types.ts # Shared AI analysis domain types
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│ └── modules/
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│ ├── message-capture/ # Discord event listeners + DB store
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│ ├── ai-moderation/ # LLM moderation pipeline (see below)
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│ ├── voice-recording/ # Voice connect + Opus→OGG recording
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│ │ └── recorder/ # decoder, segment, session, uploader, oggCrc
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│ ├── voice-pcm-ws/ # Real-time PCM → backend WebSocket (bypasses Redis)
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│ ├── attachment-upload/ # Download + (sharp) resize + upload
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│ ├── event-broadcaster/ # RedisEventPublisher + EventBroadcaster
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│ ├── command-handler/ # Redis-subscribed backend→gateway commands
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│ ├── reaction-tracking/ thread-tracking/ user-presence/
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│ ├── channel-topic/ guild-member-events/
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│ └── gateway-metrics/ # Prometheus /metrics endpoint (port 4016)
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```
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## AI moderation pipeline (`ai-moderation/`)
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LLM-only judge — no regex/heuristic classification. One orchestrator call
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handles a whole batch (text + media split internally, parallel paths).
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- `aiAnalyzer.ts` — public API: `queueMessageAnalysis`, `getAnalysisQueueStatus`,
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`startPendingAIAnalysisWorker` (recovery worker + cache-prune).
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- `batchScheduler.ts` — per-conversation debounce → `processBatch`.
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- `batchProcessor.ts` — batch lock/circuit-breaker, fans failed targets to
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individual fallback.
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- `individualFallbackProcessor.ts` — one-message-at-a-time retry path, own CB.
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- `conversationState.ts` / `circuitBreaker.ts` — per-conversation state,
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Piscina `workerPool`, `getConversationKey`.
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- `ai-analysis-worker.ts` — Piscina entry point (`batch` / `individual` jobs).
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Runs `runModerationAnalysis` off the main thread.
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- `moderationOrchestrator.ts` — exact-hash cache → batched semantic (Qdrant)
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cache → LLM. Text and media paths run in parallel.
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- `textBatchProcessor.ts` / `mediaBatchProcessor.ts` — actual LLM calls
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(one call per sub-batch, not per message).
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- `llmClient.ts` — central OpenAI-compatible chat client (streaming, retries,
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thinking-disable injection). `visionAnalyzer.ts` / `mediaAnalysisClient.ts`
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share the same router/base URL (different model alias for vision).
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- `embeddingClient.ts` + `qdrantClient.ts` — semantic cache (one embed call +
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one batched Qdrant search for all uncached targets).
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- `textCacheStore.ts` / `channelCultureStore.ts` / `userProfileStore.ts` /
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`userReputationStore.ts` — caches & learned per-channel/user state.
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### Concurrency model
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- Main thread owns the LLM semaphore (`AI_LLM_MAX_CONCURRENT`, default 5) via
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`llmClient.withLlmConcurrency`.
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- Piscina pool (`PISCINA_MAX_THREADS`, default 4) runs the heavy LLM work off
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the event loop; **each worker thread initializes its own pg Pool** (min 0,
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grows to `POSTGRES_POOL_MAX`). See "Memory & connections" below.
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## Memory & DB connections
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`MemoryMax=1G` (raised from 512M — live RSS sits at ~500 MiB, peak 508 MiB,
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so 512M left ~2% headroom and risked an OOM-kill restart). Host has 8 GB free.
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`POSTGRES_POOL_MIN=0` (default). The gateway = main process + up to 4 Piscina
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worker threads, each with its own pg Pool. With min:0 the pools stay empty
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until a query runs and drop idle clients afterward, instead of holding
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`(1 main + 4 workers) × 2 = 10` permanently-open idle connections against
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PgBouncer. The pool still grows on demand up to `POSTGRES_POOL_MAX`.
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## Event channels (Redis pub/sub)
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`discord:message:{created,updated,deleted,analyzed}`,
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`discord:attachment:{created,uploaded}`,
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`discord:voice:{started,stopped,uploaded,active_user,pcm,analyzed}`,
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`discord:analysis:queue_status`,
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`discord:reaction:{added,removed}`,
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`discord:thread:{created,deleted,updated}`,
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`discord:channel_topic:updated`,
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`discord:presence:updated`,
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`discord:guild_member:{added,removed}`.
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See `src/shared/redis-channels.ts` for the canonical names.
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## Initialization flow
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1. Validate env (Zod). Refuse to start if `AI_ANALYSIS_ENABLED` but no key.
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2. `AUTO_MIGRATE_ON_STARTUP` → run pending Drizzle migrations.
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3. `initializeDatabase()` (pg Pool, min 0).
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4. Create discord.js-selfbot-v13 client; register listeners on `ready`.
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5. Start `gmw-discord-gateway` metrics server (port `METRICS_PORT`, default 4016).
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6. `client.login(token)`.
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## Graceful shutdown
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`SIGINT`/`SIGTERM` (and uncaught transient stream errors: EPIPE / ECONNRESET /
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ERR_STREAM_DESTROYED / ERR_STREAM_WRITE_AFTER_END are treated as non-fatal):
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stop metrics → stop muxer → disconnect voice → close PCM WS → close Redis →
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close command handler → close DB → destroy client → exit.
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## Observability
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Prometheus scrapes `127.0.0.1:4016/metrics` (`bete_*` prefix). Collectors run
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per-scrape and expose: process memory/uptime, and (when AI analysis is on) live
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pipeline gauges — `ai_analysis_queued_conversations`,
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`ai_analysis_active_batch_requests`, `ai_analysis_active_individual_requests`,
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`ai_analysis_individual_in_flight`, `ai_analysis_individual_circuit_breaker_active`,
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`ai_analysis_worker_threads`, `ai_analysis_worker_threads_active`.
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## Key invariants (do not break)
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- **LLM is the only judge.** Failed LLM → `status:"error"` + recovery retry.
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Never reintroduce regex/heuristic content classification.
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- **Discord tokens are sanitized** (`discordTokens.ts`: `<:emoji:id>` →
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`[emoji:name]`, `<@id>` → `@user`, etc.) before content reaches the LLM, so
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numeric snowflake IDs never trigger false positives.
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- **Semantic cache is batched** (one embed call + one Qdrant batch search),
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not N sequential round-trips. `ensureQdrantCollection` is memoized.
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- **Streaming is mandatory** against the 9router base URL (non-stream waits for
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the full body and times out). `llmClient` aggregates SSE chunks.
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