readiness

typescript
export type CheckResult = { name: string; status: 'up' | 'down'; durationMs: number; error?: string };
export type Check = () => Promise<void>;

function withTimeout(fn: Check, ms: number): Promise<void> {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error(`timeout after ${ms}ms`)), ms);

Health checks with readiness + liveness

reliability fastify kubernetes
by codesnips 3 tabs
typescript
import { Injectable } from '@nestjs/common';
import { HealthIndicator, HealthIndicatorResult, HealthCheckError } from '@nestjs/terminus';
import { PrismaService } from '../prisma/prisma.service';

@Injectable()
export class PrismaHealthIndicator extends HealthIndicator {

NestJS Health Checks With Terminus and a Custom Prisma Indicator

nestjs terminus health-checks
by codesnips 3 tabs
java
package com.example.health;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import javax.sql.DataSource;

Custom Spring Boot Actuator Health Indicators for Database and Disk

spring-boot actuator health-check
by codesnips 3 tabs
java
package com.example.health;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

Custom Spring Boot HealthIndicator for Queue Depth on /actuator/health

spring-boot actuator health-check
by codesnips 4 tabs
javascript
const withTimeout = (promise, timeoutMs, name) => {
  let timer;
  const timeout = new Promise((_, reject) => {
    timer = setTimeout(
      () => reject(new Error(`check '${name}' timed out after ${timeoutMs}ms`)),
      timeoutMs

Express Health-Check Router With a Pluggable Dependency Checks Registry

express health-check observability
by codesnips 3 tabs
python
import time
from collections import namedtuple

from sqlalchemy import text

CheckResult = namedtuple("CheckResult", ["name", "healthy", "latency_ms", "detail"])

Flask Health-Check Blueprint Reporting Database and Redis Status as JSON

flask health-check observability
by codesnips 3 tabs
go
package health

import (
	"context"
	"sync"
	"time"

Concurrent Readiness Health Check Endpoint in Go with Timeouts

go health-check readiness
by codesnips 3 tabs