HealthMonitor.Core 1.0.2

HealthMonitor

A lightweight .NET library for monitoring application health via periodic heartbeats. Supports dependency injection, multiple named monitors, and fires Degraded / Recovered events on state transitions.

Features

• Multiple monitors — register any number of independent monitors, each with its own degraded threshold and check interval
• Two events — Degraded fires when no heartbeat is received within the threshold; Recovered fires immediately when a signal arrives while degraded
• DI-first — integrates with IServiceCollection and runs as a BackgroundService
• Keyed injection — resolve a specific monitor by name via IServiceProvider.GetRequiredKeyedService<IHealthMonitor>("name") (.NET 8+)
• Testable — IStopwatch and ISystemTimeProvider abstractions decouple timing from wall-clock time

Supported Frameworks

Installation

dotnet add package HealthMonitor.Core

Getting Started

Registration

services.AddHealthMonitor("quote-feed", opt =>
{
    opt.DegradedThreshold = TimeSpan.FromSeconds(30);
    opt.CheckInterval     = TimeSpan.FromSeconds(5);
});

AddHealthMonitor is idempotent for the shared infrastructure (hosted service, coordinator) — call it once per monitor.

Subscribing to Events

By name (keyed service, .NET 8+):

var monitor = provider.GetRequiredKeyedService<IHealthMonitor>("quote-feed");

monitor.Degraded  += (_, e) =>
    Console.WriteLine($"[{e.MonitorName}] Degraded after {e.HealthyDuration} healthy");

monitor.Recovered += (_, e) =>
    Console.WriteLine($"[{e.MonitorName}] Recovered after {e.DegradedDuration} degraded");

All monitors:

foreach (var monitor in provider.GetRequiredService<IEnumerable<IHealthMonitor>>())
{
    monitor.Degraded  += (_, e) => Console.WriteLine($"{e.MonitorName}: degraded");
    monitor.Recovered += (_, e) => Console.WriteLine($"{e.MonitorName}: recovered");
}

Sending Heartbeats

// Call Signal() whenever the monitored component is alive.
// If no signal arrives within DegradedThreshold, the Degraded event fires.
monitor.Signal();

Configuration

Event Arguments

HealthDegradedEventArgs

HealthRecoveredEventArgs

State Machine

            no signal >= DegradedThreshold
  Healthy ──────────────────────────────► Degraded
          ◄──────────────────────────────
                  Signal() called

Each monitor independently tracks its own state. The BackgroundService runs a single loop at the minimum CheckInterval across all registered monitors.

Building

dotnet build
dotnet test

Build outputs land in ./artifacts/bin/.

HealthMonitor（中文文档）

轻量级 .NET 健康监控库，通过周期性心跳信号判断组件是否存活，在状态切换时触发 Degraded / Recovered 事件。支持依赖注入、多个命名监控器。

功能特性

• 多监控器 — 可注册任意数量的独立监控器，每个监控器拥有独立的降级阈值和检查间隔
• 两种事件 — 心跳超时触发 Degraded；降级期间收到信号立即触发 Recovered
• DI 优先 — 集成 IServiceCollection，以 BackgroundService 形式运行
• 按名称注入 — 通过 IServiceProvider.GetRequiredKeyedService<IHealthMonitor>("name") 按名称解析（.NET 8+）
• 易于测试 — IStopwatch 和 ISystemTimeProvider 抽象解耦了时间依赖

支持的目标框架

安装

dotnet add package HealthMonitor.Core

快速开始

注册

services.AddHealthMonitor("quote-feed", opt =>
{
    opt.DegradedThreshold = TimeSpan.FromSeconds(30);
    opt.CheckInterval     = TimeSpan.FromSeconds(5);
});

AddHealthMonitor 对共享基础设施（托管服务、协调器）是幂等的——每个监控器调用一次即可。

订阅事件

按名称（键控服务，.NET 8+）：

var monitor = provider.GetRequiredKeyedService<IHealthMonitor>("quote-feed");

monitor.Degraded  += (_, e) =>
    Console.WriteLine($"[{e.MonitorName}] 已降级，此前健康持续 {e.HealthyDuration}");

monitor.Recovered += (_, e) =>
    Console.WriteLine($"[{e.MonitorName}] 已恢复，降级持续 {e.DegradedDuration}");

所有监控器：

foreach (var monitor in provider.GetRequiredService<IEnumerable<IHealthMonitor>>())
{
    monitor.Degraded  += (_, e) => Console.WriteLine($"{e.MonitorName}: 降级");
    monitor.Recovered += (_, e) => Console.WriteLine($"{e.MonitorName}: 恢复");
}

发送心跳

// 在被监控组件存活时调用 Signal()。
// 若在 DegradedThreshold 内未收到信号，则触发 Degraded 事件。
monitor.Signal();

配置项

事件参数

HealthDegradedEventArgs

HealthRecoveredEventArgs

状态机

            超过 DegradedThreshold 未收到信号
  健康 ─────────────────────────────────► 降级
       ◄─────────────────────────────────
                  调用 Signal()

每个监控器独立追踪自身状态。BackgroundService 以所有已注册监控器中最小的 CheckInterval 运行单一循环。

构建

dotnet build
dotnet test

构建产物位于 ./artifacts/bin/。