Graceful Shutdown

When Lambda is about to shut down an execution environment, it sends a SIGTERM signal to the runtime and a SHUTDOWN event to each registered extension. Your application can catch SIGTERM to perform cleanup tasks.

Example: Express.js

const server = app.listen(port, () => {
    console.log(`Listening on port ${port}`);
});

process.on('SIGTERM', () => {
    console.info('SIGTERM received, shutting down gracefully');
    server.close(() => {
        console.info('Server closed');
        process.exit(0);
    });
});

Use Cases

• Close database connections
• Flush logs or metrics
• Complete in-progress requests
• Release external resources

For more details, see the graceful shutdown with AWS Lambda repository.