@openstatus/health-bullmq

BullMQ probe for @openstatus/health. Counts the waiting jobs of a Queue — one LLEN against Redis — and fails the check when Redis does not answer or, with maxWaiting, when the backlog grows past a threshold.

deno add jsr:@openstatus/health jsr:@openstatus/health-bullmq
npm install @openstatus/health @openstatus/health-bullmq

import { Queue } from "bullmq";
import { createHealthHandler } from "@openstatus/health";
import { bullmqProbe } from "@openstatus/health-bullmq";

const emails = new Queue("emails", { connection: { url: env.REDIS_URL } });

Deno.serve(
  createHealthHandler({
    probes: [bullmqProbe({ queue: emails, maxWaiting: 10_000 })],
  }),
);

Reuse the Queue your application already holds: BullMQ keeps a Redis connection per Queue, so constructing one for the health endpoint would add a connection of its own. Without maxWaiting the probe only proves the queue's Redis is reachable; with it the check also turns failed when producers outrun workers, which is usually the earlier warning.

bullmqProbe({
  queue: emails,
  maxWaiting: 10_000,
  // optional overrides from the Probe contract
  name: "emails",
  critical: true,
  timeoutMs: 1000,
  skip: () => env.REDIS_URL == null,
});

Non-critical by default: a queue usually carries background work, so an outage or backlog degrades the report instead of taking the service out of rotation. Set critical: true when requests cannot complete without enqueuing.

The queue is typed structurally as { getWaitingCount(): PromiseLike<number> }, so bullmq is an optional peer dependency for its types only and the probe adds no runtime import of it. The factory throws ProbeConfigError at construction when the queue has no getWaitingCount() or maxWaiting is not a finite number of zero or more.

About openstatus

openstatus is the open-source uptime monitoring and status page platform. This package is part of @openstatus/health, the /health endpoints behind openstatus's own services, extracted so any JavaScript server can expose one. Point an openstatus monitor at the endpoint and assert on status in the body to be alerted on degraded before it becomes unhealthy.

Source: github.com/openstatusHQ/health. Issues and PRs welcome.

License

MIT