How do you handle database connection pooling and health checks in NestJS?

Q: How do you handle database connection pooling and health checks in NestJS?

// TypeORM connection pool settings TypeOrmModule.forRoot({ type: 'postgres', // ... extra: { max: 20, // max pool size min: 5, // min idle connections idleTimeoutMillis: 30000, // release idle connections after 30s connectionTimeoutMillis: 2000, // fail fast if no connection available }, }) // Health check — npm i @nestjs/terminus @Module({ imports: [TerminusModule], controllers: [HealthController], }) export class HealthModule {} @Controller('health') export class HealthController { constructor( private health: HealthCheckService, private db: TypeOrmHealthIndicator, ) {} @Get() @HealthCheck() check() { return this.health.check([ () => this.db.pingCheck('database'), ]); } } // GET /health // { status: 'ok', info: { database: { status: 'up' } } } max pool size should not exceed the database server's max_connections setting divided by the number of app instances. connectionTimeoutMillis: 2000 makes requests fail fast when the pool is exhausted rather than queuing indefinitely. @nestjs/terminus provides health indicators for TypeORM, Prisma, Redis, HTTP, DNS, and custom checks. Health endpoints are probed by Kubernetes liveness and readiness probes — keep them fast and lightweight. Use TypeOrmHealthIndicator.pingCheck() for TypeORM; write a custom indicator for Prisma using prisma.$queryRaw.

Difficulty: 5/10

connection pooling, health checks, NestJS integration

Configure the pool size via the extra option in TypeOrmModule.forRoot(). Use @nestjs/terminus with TypeOrmHealthIndicator for health checks. The health endpoint pings the database and returns a structured status object that load balancers and orchestrators can poll.

Connection pool configuration and health check endpoint

Connection pool and health check guidelines:

1
max pool size should not exceed the database server's max_connections setting divided by the number of app instances.
2
connectionTimeoutMillis: 2000 makes requests fail fast when the pool is exhausted rather than queuing indefinitely.

How do you handle database connection pooling and health checks in NestJS?

Difficulty: 5/10

connection pooling, health checks, NestJS integration

Configure the pool size via the extra option in TypeOrmModule.forRoot(). Use @nestjs/terminus with TypeOrmHealthIndicator for health checks. The health endpoint pings the database and returns a structured status object that load balancers and orchestrators can poll.

Connection pool configuration and health check endpoint

Connection pool and health check guidelines:

1
max pool size should not exceed the database server's max_connections setting divided by the number of app instances.
2
connectionTimeoutMillis: 2000 makes requests fail fast when the pool is exhausted rather than queuing indefinitely.

How do you handle database connection pooling and health checks in NestJS?

Configure the pool size via the extra option in TypeOrmModule.forRoot(). Use @nestjs/terminus with TypeOrmHealthIndicator for health checks. The health endpoint pings the database and returns a structured status object that load balancers and orchestrators can poll.

How do you handle database connection pooling and health checks in NestJS?

Configure the pool size via the extra option in TypeOrmModule.forRoot(). Use @nestjs/terminus with TypeOrmHealthIndicator for health checks. The health endpoint pings the database and returns a structured status object that load balancers and orchestrators can poll.

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