Stop memory leaks in Node.js. Learn to capture, compare, and analyze heap snapshots to find and fix the root cause of memory growth.

HaloDoc is a healthcare technology platform that offers telemedicine services, online pharmacy, and health information resources to users in Indonesia. Through its platform, HaloDoc aims to improve access to healthcare services, empower patients to take control of their health, and facilitate collaboration between healthcare providers. Developers can learn from HaloDoc's innovative use of technology to address healthcare challenges, leveraging telemedicine, artificial intelligence, and data analytics to enhance patient care and outcomes.

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Memory leaks in Node.js applications cause gradual memory growth until containers crash or restart. Heap snapshots provide detailed dumps of JavaScript memory at specific moments, revealing which objects consume memory and why they aren't garbage collected. The article demonstrates capturing snapshots using Node.js V8 API, triggering them on app start, via SIGUSR2 signals, and automatically during OOM events. Analysis involves comparing multiple snapshots in Chrome DevTools to identify growing objects, examining retained sizes, and tracing retainer chains to find root causes. Common leak patterns include lingering timers, unremoved event listeners, unclosed RxJS subscriptions, and closures retaining large objects. The solution includes storing snapshots securely in S3 with encryption and automatic expiry, enabling systematic debugging of production memory issues.

Find & Fix Node.js Memory Leaks with Heap Snapshots