Node.js Graceful Shutdown in Production: SIGTERM, In-Flight Draining, and Zero-Downtime Deploys

Your deployment pipeline fires. Kubernetes sends SIGTERM. Your Node.js process has 47 in-flight HTTP requests, 3 BullMQ jobs mid-execution, and a PostgreSQL connection pool with 8 active transactions. What happens next?

If you haven't explicitly handled shutdown, the answer is: those requests die, those jobs fail, and your users see 502 errors during every deploy. In 2026, with rolling deployments, canary releases, and sub-second restart cycles, graceful shutdown is not optional — it's the difference between a professional service and a brittle one.

This guide covers the complete graceful shutdown lifecycle for production Node.js services: signal handling, in-flight HTTP request draining, database cleanup, job queue flushing, and Kubernetes preStop hook integration.

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Why Shutdown Fails Without Explicit Handling

Node.js exits on unhandled SIGTERM with an immediate kill — no cleanup, no draining. When Kubernetes rolls out a new pod, it:

1. Sends SIGTERM to the old pod
2. Waits terminationGracePeriodSeconds (default 30s)
3. Sends SIGKILL if the process hasn't exited

Without explicit handling, step 1 kills your process instantly. In-flight requests get a TCP RST. Active database transactions are rolled back. Background jobs lose their state.

The fix is a shutdown handler that catches SIGTERM, stops accepting new work, completes existing work, and exits cleanly.

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The Basic Shutdown Pattern

// shutdown.js
const logger = require('./logger'); // pino or winston

let isShuttingDown = false;

async function shutdown(signal) {
  if (isShuttingDown) return;
  isShuttingDown = true;

  logger.info({ signal }, 'Shutdown initiated');

  try {
    await drainHttpServer();
    await flushJobQueues();
    await closeDbPool();
    await closeRedis();
    logger.info('Graceful shutdown complete');
    process.exit(0);
  } catch (err) {
    logger.error({ err }, 'Shutdown error — forcing exit');
    process.exit(1);
  }
}

process.on('SIGTERM', () => shutdown('SIGTERM'));
process.on('SIGINT',  () => shutdown('SIGINT'));

// Unhandled rejection guard — don't silently swallow errors
process.on('unhandledRejection', (reason) => {
  logger.error({ reason }, 'Unhandled rejection — initiating shutdown');
  shutdown('unhandledRejection');
});

The isShuttingDown flag prevents double-shutdown if both SIGTERM and SIGINT fire. Exit code 0 signals success to the orchestrator; exit code 1 signals failure (Kubernetes may restart the pod or flag the rollout as failed).

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Draining In-Flight HTTP Requests

The HTTP server must stop accepting new connections but let existing requests complete. Node's built-in server.close() does exactly that — it stops the listening socket but keeps alive connections open.

The problem: keep-alive connections (default in HTTP/1.1 and mandatory in HTTP/2) aren't closed by server.close(). You need to track them and force-close idle ones.

// http-server.js
const http = require('http');
const app  = require('./app');   // Express/Fastify app

const server = http.createServer(app);

// Track all active connections
const connections = new Set();

server.on('connection', (socket) => {
  connections.add(socket);
  socket.on('close', () => connections.delete(socket));
});

async function drainHttpServer() {
  return new Promise((resolve, reject) => {
    const DRAIN_TIMEOUT_MS = 20_000;

    // Stop accepting new connections
    server.close((err) => {
      if (err) return reject(err);
      resolve();
    });

    // Force-close idle keep-alive connections after a short delay
    setTimeout(() => {
      for (const socket of connections) {
        socket.destroy();
      }
    }, 5_000); // give in-flight requests 5s to complete

    // Hard timeout failsafe
    setTimeout(() => {
      reject(new Error(`HTTP drain timed out after ${DRAIN_TIMEOUT_MS}ms`));
    }, DRAIN_TIMEOUT_MS);
  });
}

module.exports = { server, drainHttpServer };

Fastify makes this even cleaner — fastify.close() handles keep-alive and returns a promise:

async function drainHttpServer() {
  await fastify.close(); // drains connections, runs onClose hooks
}

Express users should use the http-terminator package, which handles the keep-alive edge case with proper socket-level tracking and configurable grace periods.

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Readiness Probe Integration

During shutdown, you want Kubernetes to stop routing traffic before you stop accepting connections — not after. Use a readiness probe endpoint that returns 503 when isShuttingDown is true:

// In Express/Fastify app
app.get('/health/ready', (req, res) => {
  if (isShuttingDown) {
    return res.status(503).json({ status: 'shutting_down' });
  }
  res.json({ status: 'ready' });
});

Update your Kubernetes deployment to set the readiness probe to fail fast on shutdown:

readinessProbe:
  httpGet:
    path: /health/ready
    port: 3000
  periodSeconds: 2
  failureThreshold: 1   # remove from load balancer after 1 failed check

When Kubernetes sends SIGTERM, your process immediately fails readiness checks (within 2 seconds), gets removed from the service's endpoint list, and then drains the remaining in-flight requests — which are now genuinely the last ones, since the load balancer has stopped routing new traffic.

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BullMQ Job Queue Shutdown

BullMQ workers process jobs asynchronously. Abruptly killing a worker mid-job will mark the job as failed or leave it in an indeterminate state depending on your removeOnComplete/removeOnFail settings.

const { Worker } = require('bullmq');
const { redis }  = require('./redis');

const emailWorker = new Worker('email-queue', processEmail, {
  connection: redis,
  concurrency: 5,
});

async function flushJobQueues() {
  logger.info('Closing BullMQ workers...');

  // close() waits for currently-running jobs to finish, then stops
  await emailWorker.close();

  // If you have multiple workers:
  await Promise.all([
    emailWorker.close(),
    reportWorker.close(),
    notificationWorker.close(),
  ]);

  logger.info('All BullMQ workers closed');
}

worker.close() signals the worker to stop picking up new jobs. It waits for running jobs to complete (up to closeTimeout, default 5000ms). Jobs that exceed the timeout are moved to failed state, where your retry policy takes over — they'll be re-queued when the new pod starts.

For long-running jobs (video processing, report generation), set a high closeTimeout:

await heavyWorker.close(/* timeout */ 25_000);

---

Database Connection Pool Cleanup

PostgreSQL connections left open without proper cleanup cause too many connections errors and potential data integrity issues if transactions are abandoned mid-operation.

With pg (node-postgres):

const { Pool } = require('pg');
const pool = new Pool({ max: 20, connectionString: process.env.DATABASE_URL });

async function closeDbPool() {
  logger.info('Draining PostgreSQL pool...');
  await pool.end(); // waits for active queries to complete, then closes all connections
  logger.info('PostgreSQL pool closed');
}

With Prisma:

const { PrismaClient } = require('@prisma/client');
const prisma = new PrismaClient();

async function closeDbPool() {
  await prisma.$disconnect();
}

With Mongoose (MongoDB):

async function closeDbPool() {
  await mongoose.connection.close();
}

The key: always await the close — don't fire-and-forget. An unawaited pool.end() will let the process exit before connections are fully released, causing connection leaks in the database server.

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Redis Cleanup

Redis connections should be closed after all workers and HTTP requests have been handled, since workers depend on Redis for queue coordination:

const Redis = require('ioredis');
const redis = new Redis(process.env.REDIS_URL);

async function closeRedis() {
  logger.info('Closing Redis connection...');
  await redis.quit(); // sends QUIT command, waits for pending commands to complete
  logger.info('Redis connection closed');
}

Use redis.quit() over redis.disconnect() — quit sends a QUIT command and waits for the server acknowledgment, ensuring pending pipeline commands flush first.

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Kubernetes preStop Hook

Kubernetes has a race condition: it sends SIGTERM and simultaneously removes the pod from service endpoints — but the endpoint update propagates through kube-proxy asynchronously. Requests can still arrive after SIGTERM for 1-3 seconds.

The preStop hook runs before SIGTERM and delays the pod deletion, giving the endpoint update time to propagate:

lifecycle:
  preStop:
    exec:
      command: ["/bin/sh", "-c", "sleep 5"]

With this hook, the sequence is:

1. Kubernetes schedules pod for termination
2. preStop hook runs: sleep 5
3. During those 5 seconds, endpoint propagation completes — no new traffic
4. SIGTERM sent → your shutdown handler runs → clean drain
5. Pod exits cleanly

Adjust terminationGracePeriodSeconds to be larger than your expected drain time plus preStop duration:

terminationGracePeriodSeconds: 60  # preStop(5s) + HTTP drain(20s) + buffer

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Full Shutdown Orchestration

Putting it all together — a production-ready shutdown module:

// shutdown-manager.js
const { drainHttpServer } = require('./http-server');
const { flushJobQueues }  = require('./workers');
const { closeDbPool }     = require('./db');
const { closeRedis }      = require('./redis');
const logger = require('./logger');

let isShuttingDown = false;

async function shutdown(signal) {
  if (isShuttingDown) {
    logger.warn('Shutdown already in progress, ignoring duplicate signal');
    return;
  }
  isShuttingDown = true;

  const start = Date.now();
  logger.info({ signal }, '🛑 Shutdown initiated');

  const ABSOLUTE_TIMEOUT = 25_000;
  const timeoutHandle = setTimeout(() => {
    logger.error('Shutdown exceeded absolute timeout — forcing exit');
    process.exit(1);
  }, ABSOLUTE_TIMEOUT);

  try {
    // 1. Stop accepting new HTTP connections (readiness probe fails immediately)
    // 2. Drain in-flight requests
    await drainHttpServer();
    logger.info('HTTP server drained');

    // 3. Stop workers from picking up new jobs, finish current jobs
    await flushJobQueues();
    logger.info('Job queues flushed');

    // 4. Close DB pool (waits for active queries)
    await closeDbPool();
    logger.info('Database pool closed');

    // 5. Close Redis last (workers need it until they're done)
    await closeRedis();
    logger.info('Redis closed');

    clearTimeout(timeoutHandle);
    logger.info({ durationMs: Date.now() - start }, '✅ Graceful shutdown complete');
    process.exit(0);
  } catch (err) {
    clearTimeout(timeoutHandle);
    logger.error({ err, durationMs: Date.now() - start }, 'Shutdown failed');
    process.exit(1);
  }
}

module.exports = { shutdown, isShuttingDown: () => isShuttingDown };

// Attach signal handlers immediately on require
process.on('SIGTERM', () => shutdown('SIGTERM'));
process.on('SIGINT',  () => shutdown('SIGINT'));
process.on('unhandledRejection', (reason) => {
  logger.error({ reason }, 'Unhandled rejection');
  shutdown('unhandledRejection');
});

Require this module at the top of your entrypoint (server.js) and signals are handled for the lifetime of the process.

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Production Checklist

• [ ] SIGTERM handler registered before any async startup code
• [ ] HTTP server drains keep-alive connections, not just incoming
• [ ] Readiness probe returns 503 immediately when isShuttingDown is true
• [ ] BullMQ workers use worker.close() — not process.kill()
• [ ] Database pool awaited on pool.end() / prisma.$disconnect()
• [ ] Redis uses redis.quit(), not redis.disconnect()
• [ ] Absolute timeout forces exit if drain takes too long (prevents hang)
• [ ] preStop hook adds a 5-second sleep before SIGTERM
• [ ] terminationGracePeriodSeconds > preStop + max expected drain time
• [ ] Shutdown tested with kill -SIGTERM <pid> under load before prod

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Key Takeaways

Graceful shutdown is a first-class production concern. In Kubernetes environments with frequent rolling deploys, it directly determines whether your users experience dropped requests. The pattern is always the same: fail readiness, drain HTTP, flush queues, close DB, close Redis, exit cleanly. Implement it once in a shared shutdown-manager.js and all services in your monorepo get it for free.

The 30-line shutdown module above has prevented hundreds of 502 errors per deploy across production services. Build it in before you need it.

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