Add per-server telemetry request diagnostics

src/lib/server/db/schema.sql

@@ -367,6 +367,24 @@ CREATE TABLE IF NOT EXISTS server_telemetry (
     received_at TEXT NOT NULL,
     payload TEXT
 );
+-- Request diagnostics survive registry removal and also capture unknown names.
+-- Bounded independently of the latest scoreboard and permanent leaderboard.
+CREATE TABLE IF NOT EXISTS telemetry_requests (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    server TEXT NOT NULL,
+    received_at TEXT NOT NULL,
+    status INTEGER NOT NULL,
+    error TEXT,
+    event TEXT,
+    map TEXT,
+    round INTEGER,
+    player_count INTEGER,
+    content_type TEXT,
+    payload TEXT NOT NULL,
+    payload_truncated INTEGER NOT NULL DEFAULT 0
+);
+CREATE INDEX IF NOT EXISTS idx_telemetry_requests_server ON telemetry_requests(server, id DESC);
+CREATE INDEX IF NOT EXISTS idx_telemetry_requests_received ON telemetry_requests(received_at);
 -- Lifecycle history deliberately survives removal of the server registry row.
 CREATE TABLE IF NOT EXISTS server_deployments (
     id TEXT PRIMARY KEY,

src/lib/server/fleet/telemetry-requests.ts

@@ -0,0 +1,50 @@
+import { db } from '../db/index.js';
+import { TELEMETRY_REQUEST_RETENTION, type TelemetryRequestLogEntry } from '../../telemetry-diagnostics.js';
+
+const MAX_PAYLOAD_LENGTH = 16 * 1024;
+// Bound storage even when requests claim many different, unregistered names.
+const MAX_REQUESTS = 10_000;
+const cutoff = () => new Date(Date.now() - TELEMETRY_REQUEST_RETENTION.maxAgeDays * 86_400_000).toISOString();
+const textField = (value: unknown) => typeof value === 'string' ? value.slice(0, 255) : null;
+
+export function recordTelemetryRequest(input: {
+    value: unknown;
+    receivedAt: string;
+    status: number;
+    error: string | null;
+    contentType: string | null;
+}): void {
+    // Use only the top-level JSON field, never a player's name or a substring.
+    // Malformed JSON cannot be reliably attributed to an individual server.
+    if (!input.value || typeof input.value !== 'object' || Array.isArray(input.value)) return;
+    const body = input.value as Record<string, unknown>;
+    if (typeof body.server !== 'string' || !body.server.trim() || body.server.length > 255) return;
+    const payload = JSON.stringify(body);
+    const handle = db();
+    handle.transaction(() => {
+        handle.prepare(`INSERT INTO telemetry_requests
+            (server, received_at, status, error, event, map, round, player_count, content_type, payload, payload_truncated)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`).run(
+            body.server, input.receivedAt, input.status, input.error?.slice(0, 2000) ?? null,
+            textField(body.event), textField(body.map),
+            Number.isSafeInteger(body.round) ? body.round as number : null,
+            Array.isArray(body.players) ? body.players.length : null,
+            textField(input.contentType), payload.slice(0, MAX_PAYLOAD_LENGTH), Number(payload.length > MAX_PAYLOAD_LENGTH)
+        );
+        handle.prepare('DELETE FROM telemetry_requests WHERE received_at < ?').run(cutoff());
+        handle.prepare(`DELETE FROM telemetry_requests WHERE server = ? AND id <= (
+            SELECT id FROM telemetry_requests WHERE server = ? ORDER BY id DESC LIMIT 1 OFFSET ?
+        )`).run(body.server, body.server, TELEMETRY_REQUEST_RETENTION.maxPerServer);
+        handle.prepare(`DELETE FROM telemetry_requests WHERE id <= (
+            SELECT id FROM telemetry_requests ORDER BY id DESC LIMIT 1 OFFSET ?
+        )`).run(MAX_REQUESTS);
+    })();
+}
+
+export function listTelemetryRequests(server: string): TelemetryRequestLogEntry[] {
+    const rows = db().prepare(`SELECT id, server, received_at AS receivedAt, status, error, event, map, round,
+        player_count AS playerCount, content_type AS contentType, payload, payload_truncated AS payloadTruncated
+        FROM telemetry_requests WHERE server = ? AND received_at >= ? ORDER BY id DESC LIMIT ?`)
+        .all(server, cutoff(), TELEMETRY_REQUEST_RETENTION.maxPerServer) as Array<Omit<TelemetryRequestLogEntry, 'payloadTruncated'> & { payloadTruncated: number }>;
+    return rows.map(row => ({ ...row, payloadTruncated: !!row.payloadTruncated }));
+}