Memory Leak Detection
Table of Contents
Overview
Identify and fix memory leaks to prevent out-of-memory crashes and optimize application performance.
When to Use
- Memory usage growing over time
- Out of memory (OOM) errors
- Performance degradation
- Container restarts
- High memory consumption
Quick Start
Minimal working example:
import v8 from "v8";
import fs from "fs";
class MemoryProfiler {
takeSnapshot(filename: string): void {
const snapshot = v8.writeHeapSnapshot(filename);
console.log(`Heap snapshot saved to ${snapshot}`);
}
getMemoryUsage(): NodeJS.MemoryUsage {
return process.memoryUsage();
}
formatMemory(bytes: number): string {
return `${(bytes / 1024 / 1024).toFixed(2)} MB`;
}
printMemoryUsage(): void {
const usage = this.getMemoryUsage();
console.log("Memory Usage:");
console.log(` RSS: ${this.formatMemory(usage.rss)}`);
console.log(` Heap Total: ${this.formatMemory(usage.heapTotal)}`);
console.log(` Heap Used: ${this.formatMemory(usage.heapUsed)}`);
console.log(` External: ${this.formatMemory(usage.external)}`);
// ... (see reference guides for full implementation)Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| Node.js Heap Snapshots | Node.js Heap Snapshots |
| Memory Leak Detection Middleware | Memory Leak Detection Middleware |
| Common Memory Leak Patterns | Common Memory Leak Patterns |
| Python Memory Profiling | Python Memory Profiling |
| WeakMap/WeakRef for Cache | WeakMap/WeakRef for Cache |
| Memory Monitoring in Production | Memory Monitoring in Production |
Best Practices
✅ DO
- Remove event listeners when done
- Clear timers and intervals
- Use WeakMap/WeakRef for caches
- Limit cache sizes
- Monitor memory in production
- Profile regularly
- Clean up after tests
❌ DON'T
- Create circular references
- Hold references to large objects unnecessarily
- Forget to clean up resources
- Ignore memory growth
- Skip WeakMap for object caches