chore: import upstream snapshot with attribution

2026-07-13 13:32:57 +08:00
commit cd420f9332
4811 changed files with 884702 additions and 0 deletions
@@ -0,0 +1,65 @@
+import { logger } from "~/services/logger.server";
+import { getMollifierBuffer } from "./mollifierBuffer.server";
+import { reportDrainingCount } from "./mollifierTelemetry.server";
+
+// How often we ZCARD the draining-tracker set. Each poll is a single
+// O(1) Redis call, so cadence is bounded by "how fresh do we want the
+// gauge?" rather than cost. 15s gives a tight-enough window to spot a
+// brief OOM-induced spike without burning RTTs, and lines up well with
+// typical Prometheus scrape intervals.
+const POLL_INTERVAL_MS = 15_000;
+
+let intervalHandle: ReturnType<typeof setInterval> | null = null;
+
+// Polls `mollifier:draining` cardinality on an interval and feeds the
+// gauge in `mollifierTelemetry.server.ts`. Started from the drainer
+// worker bootstrap (alongside `drainer.start()`) so it runs on the same
+// pods that actually pop/ack entries — observability is colocated with
+// the lifecycle.
+//
+// Idempotent: a second call is a no-op (Remix dev hot-reload re-runs
+// the bootstrap; the existing interval keeps ticking).
+export function startMollifierDrainingGauge(
+  opts: {
+    intervalMs?: number;
+    getBuffer?: typeof getMollifierBuffer;
+  } = {}
+): void {
+  if (intervalHandle !== null) return;
+
+  const intervalMs = opts.intervalMs ?? POLL_INTERVAL_MS;
+  const getBuffer = opts.getBuffer ?? getMollifierBuffer;
+
+  // Fire one poll immediately so the gauge populates before the first
+  // scrape rather than reading 0 for a full interval after boot.
+  const tick = async () => {
+    const buffer = getBuffer();
+    if (!buffer) return;
+    try {
+      const count = await buffer.getDrainingCount();
+      reportDrainingCount(count);
+    } catch (err) {
+      // Transient Redis blip — don't tank the loop, just leave the
+      // gauge at its last-known value. A sustained Redis outage will
+      // surface via the drainer's own alerts long before this gauge
+      // staleness becomes a primary signal.
+      logger.warn("Mollifier draining gauge poll failed; keeping previous value", { err });
+    }
+  };
+
+  void tick();
+  // unref so the interval doesn't keep the process alive past
+  // graceful shutdown — the gauge is best-effort, not a flush boundary.
+  intervalHandle = setInterval(() => {
+    void tick();
+  }, intervalMs);
+  intervalHandle.unref?.();
+}
+
+// Test seam. Production code never calls this; lifecycle is implicitly
+// process-end.
+export function stopMollifierDrainingGauge(): void {
+  if (intervalHandle === null) return;
+  clearInterval(intervalHandle);
+  intervalHandle = null;
+}