NestJS 性能优化：从应用到部署的最佳实践

在上一篇文章中，我们介绍了 NestJS 的微服务架构实现。本文将深入探讨 NestJS 应用的性能优化策略，从应用层到部署层面提供全方位的优化指南。

应用层优化

1. 路由优化

// src/modules/users/users.controller.ts
import { Controller, Get, UseInterceptors, CacheInterceptor } from '@nestjs/common';
import { UsersService } from './users.service';@Controller('users')
@UseInterceptors(CacheInterceptor)
export class UsersController {constructor(private readonly usersService: UsersService) {}// 使用路由参数而不是查询参数，提高路由匹配效率@Get(':id')async findOne(@Param('id') id: string) {return this.usersService.findOne(id);}// 避免深层嵌套路由@Get(':id/profile')async getProfile(@Param('id') id: string) {return this.usersService.getProfile(id);}
}

2. 数据序列化优化

// src/interceptors/transform.interceptor.ts
import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { classToPlain } from 'class-transformer';@Injectable()
export class TransformInterceptor implements NestInterceptor {intercept(context: ExecutionContext, next: CallHandler): Observable<any> {return next.handle().pipe(map(data => {// 使用 class-transformer 进行高效的数据序列化return classToPlain(data, { excludeExtraneousValues: true,enableCircularCheck: false });}),);}
}

数据库优化

1. 查询优化

// src/modules/posts/posts.service.ts
import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Post } from './post.entity';@Injectable()
export class PostsService {constructor(@InjectRepository(Post)private postsRepository: Repository<Post>,) {}async findAll(page: number, limit: number) {// 使用分页查询const [posts, total] = await this.postsRepository.createQueryBuilder('post').leftJoinAndSelect('post.author', 'author')// 只选择需要的字段.select(['post.id', 'post.title', 'author.name'])// 添加索引字段的排序.orderBy('post.createdAt', 'DESC')// 使用分页.skip((page - 1) * limit).take(limit)// 缓存查询结果.cache(true).getManyAndCount();return { posts, total };}
}

2. 索引优化

// src/entities/user.entity.ts
import { Entity, Column, Index } from 'typeorm';@Entity()
export class User {@Column()@Index() // 为经常查询的字段添加索引email: string;@Column()@Index() // 为经常排序的字段添加索引createdAt: Date;// 复合索引@Index(['firstName', 'lastName'])@Column()firstName: string;@Column()lastName: string;
}

缓存策略

1. Redis 缓存集成

// src/config/cache.config.ts
import { CacheModule } from '@nestjs/common';
import * as redisStore from 'cache-manager-redis-store';export const cacheConfig = {imports: [CacheModule.register({store: redisStore,host: process.env.REDIS_HOST,port: process.env.REDIS_PORT,ttl: 60 * 60, // 1 hourmax: 100, // 最大缓存数}),],
};// src/modules/products/products.service.ts
import { Injectable, Inject, CACHE_MANAGER } from '@nestjs/common';
import { Cache } from 'cache-manager';@Injectable()
export class ProductsService {constructor(@Inject(CACHE_MANAGER) private cacheManager: Cache,) {}async getProduct(id: string) {// 先从缓存获取let product = await this.cacheManager.get(`product:${id}`);if (!product) {// 缓存未命中，从数据库获取product = await this.productRepository.findOne(id);// 设置缓存await this.cacheManager.set(`product:${id}`, product, { ttl: 3600 });}return product;}
}

2. 多级缓存策略

// src/services/cache.service.ts
import { Injectable } from '@nestjs/common';
import { Cache } from 'cache-manager';
import * as NodeCache from 'node-cache';@Injectable()
export class CacheService {private localCache: NodeCache;constructor(@Inject(CACHE_MANAGER) private redisCache: Cache,) {this.localCache = new NodeCache({stdTTL: 60, // 本地缓存 1 分钟checkperiod: 120,});}async get(key: string) {// 1. 检查本地缓存let data = this.localCache.get(key);if (data) return data;// 2. 检查 Redis 缓存data = await this.redisCache.get(key);if (data) {// 将数据放入本地缓存this.localCache.set(key, data);return data;}return null;}async set(key: string, value: any, ttl?: number) {// 同时更新本地缓存和 Redis 缓存this.localCache.set(key, value, ttl);await this.redisCache.set(key, value, { ttl });}
}

内存管理

1. 内存泄漏防护

// src/decorators/memory-safe.decorator.ts
import { applyDecorators, SetMetadata } from '@nestjs/common';export function MemorySafe(options: { timeout?: number } = {}) {return applyDecorators(SetMetadata('memory-safe', true),SetMetadata('timeout', options.timeout || 30000),);
}// src/interceptors/memory-guard.interceptor.ts
import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { Observable } from 'rxjs';
import { timeout } from 'rxjs/operators';@Injectable()
export class MemoryGuardInterceptor implements NestInterceptor {constructor(private reflector: Reflector) {}intercept(context: ExecutionContext, next: CallHandler): Observable<any> {const isMemorySafe = this.reflector.get('memory-safe', context.getHandler());const timeoutValue = this.reflector.get('timeout', context.getHandler());if (isMemorySafe) {return next.handle().pipe(timeout(timeoutValue),);}return next.handle();}
}

2. 垃圾回收优化

// src/main.ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import * as v8 from 'v8';async function bootstrap() {// 配置垃圾回收v8.setFlagsFromString('--max_old_space_size=4096');const app = await NestFactory.create(AppModule);// 定期强制垃圾回收setInterval(() => {global.gc();}, 30000);await app.listen(3000);
}
bootstrap();

部署优化

1. PM2 集群配置

// ecosystem.config.js
module.exports = {apps: [{name: 'nestjs-app',script: 'dist/main.js',instances: 'max', // 根据 CPU 核心数自动设置实例数exec_mode: 'cluster',autorestart: true,watch: false,max_memory_restart: '1G',env: {NODE_ENV: 'production',},}],
};

2. Nginx 负载均衡

# nginx.conf
upstream nestjs_upstream {least_conn; # 最少连接数负载均衡server 127.0.0.1:3000;server 127.0.0.1:3001;server 127.0.0.1:3002;keepalive 32; # 保持连接数
}server {listen 80;server_name example.com;location / {proxy_pass http://nestjs_upstream;proxy_http_version 1.1;proxy_set_header Upgrade $http_upgrade;proxy_set_header Connection 'upgrade';proxy_set_header Host $host;proxy_cache_bypass $http_upgrade;# 开启 gzip 压缩gzip on;gzip_types text/plain application/json;gzip_min_length 1000;# 客户端缓存设置add_header Cache-Control "public, max-age=3600";}
}

监控与性能分析

1. 性能监控集成

// src/modules/monitoring/monitoring.service.ts
import { Injectable } from '@nestjs/common';
import * as prometheus from 'prom-client';@Injectable()
export class MonitoringService {private readonly requestDuration: prometheus.Histogram;private readonly activeConnections: prometheus.Gauge;constructor() {// 初始化 Prometheus 指标this.requestDuration = new prometheus.Histogram({name: 'http_request_duration_seconds',help: 'Duration of HTTP requests in seconds',labelNames: ['method', 'route', 'status'],buckets: [0.1, 0.5, 1, 2, 5],});this.activeConnections = new prometheus.Gauge({name: 'active_connections',help: 'Number of active connections',});}recordRequestDuration(method: string, route: string, status: number, duration: number) {this.requestDuration.labels(method, route, status.toString()).observe(duration);}incrementConnections() {this.activeConnections.inc();}decrementConnections() {this.activeConnections.dec();}
}

2. 日志优化

// src/modules/logging/winston.config.ts
import { WinstonModule } from 'nest-winston';
import * as winston from 'winston';
import 'winston-daily-rotate-file';export const winstonConfig = {imports: [WinstonModule.forRoot({transports: [// 控制台日志new winston.transports.Console({format: winston.format.combine(winston.format.timestamp(),winston.format.colorize(),winston.format.simple(),),}),// 文件日志（按日期轮转）new winston.transports.DailyRotateFile({filename: 'logs/application-%DATE%.log',datePattern: 'YYYY-MM-DD',zippedArchive: true,maxSize: '20m',maxFiles: '14d',format: winston.format.combine(winston.format.timestamp(),winston.format.json(),),}),],}),],
};