Actuator 与可观测性：健康检查、指标与监控

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-actuator</artifactId></dependency>

@Component("smsProvider")public class SmsProviderHealthIndicator implements HealthIndicator {    private static final Logger log = LoggerFactory.getLogger(SmsProviderHealthIndicator.class);    private final SmsClient smsClient;    public SmsProviderHealthIndicator(SmsClient smsClient) {        this.smsClient = smsClient;    }    @Override    public Health health() {        try {            long latency = smsClient.ping();            return Health.up()                    .withDetail("latencyMs", latency)                    .withDetail("endpoint", smsClient.getEndpoint())                    .build();        } catch (Exception ex) {            log.warn("短信服务探活失败", ex);            return Health.down(ex).withDetail("endpoint", smsClient.getEndpoint()).build();        }    }}

<dependency>    <groupId>io.micrometer</groupId>    <artifactId>micrometer-registry-prometheus</artifactId></dependency>

# HELP http_server_requests_seconds Timer for HTTP server requests# TYPE http_server_requests_seconds histogramhttp_server_requests_seconds_count{method="POST",uri="/api/orders",status="201"} 1284.0http_server_requests_seconds_sum{method="POST",uri="/api/orders",status="201"} 41.52http_server_requests_seconds_bucket{method="POST",uri="/api/orders",status="201",le="0.1"} 990.0http_server_requests_seconds_bucket{method="POST",uri="/api/orders",status="201",le="0.5"} 1270.0# HELP beeorder_order_created_total Orders created successfully# TYPE beeorder_order_created_total counterbeeorder_order_created_total 13245.0

scrape_configs:  - job_name: beeorder    metrics_path: /actuator/prometheus    scrape_interval: 15s    static_configs:      - targets: ['beeorder-app:9090']

<plugin>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-maven-plugin</artifactId>    <executions>        <execution>            <goals>                <goal>build-info</goal>   <!-- 生成 META-INF/build-info.properties -->            </goals>        </execution>    </executions></plugin>

management:  info:    git:      mode: full        # 需要 spring-boot-starter-actuator + git-commit-id 插件    env:      enabled: true

<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">    <modelVersion>4.0.0</modelVersion>    <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-parent</artifactId>        <version>3.3.4</version>        <relativePath/>    </parent>    <groupId>com.example</groupId>    <artifactId>monitor-lab</artifactId>    <version>0.0.1-SNAPSHOT</version>    <properties>        <java.version>17</java.version>    </properties>    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <!-- 监控本体 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-actuator</artifactId>        </dependency>        <!-- Prometheus 文本格式注册表 -->        <dependency>            <groupId>io.micrometer</groupId>            <artifactId>micrometer-registry-prometheus</artifactId>        </dependency>        <!-- 制造一个真实的 db 健康指示器 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-jdbc</artifactId>        </dependency>        <dependency>            <groupId>com.h2database</groupId>            <artifactId>h2</artifactId>            <scope>runtime</scope>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>                <executions>                    <execution>                        <goals>                            <goal>build-info</goal>   <!-- 让 /actuator/info 有内容 -->                        </goals>                    </execution>                </executions>            </plugin>        </plugins>    </build></project>

server:  port: 8080                      # 业务端口：对公网开放spring:  application:    name: monitor-lab  datasource:    url: jdbc:h2:mem:lab;DB_CLOSE_DELAY=-1    driver-class-name: org.h2.Drivermanagement:  server:    port: 9090                    # 管理端口：仅内网可达  endpoints:    web:      base-path: /actuator      exposure:        include: health,info,metrics,prometheus   # 白名单，绝不写 *  endpoint:    health:      show-details: when_authorized      group:        liveness:          include: ping        readiness:          include: db,diskSpace  info:    env:      enabled: truelogging:  level:    com.example.monitorlab: INFO

package com.example.monitorlab;import java.util.concurrent.atomic.AtomicLong;import org.springframework.boot.actuate.health.Health;import org.springframework.boot.actuate.health.HealthIndicator;import org.springframework.stereotype.Component;@Component("inventoryCache")public class InventoryCacheHealthIndicator implements HealthIndicator {    private final AtomicLong lastSyncOkAt = new AtomicLong(System.currentTimeMillis());    @Override    public Health health() {        long staleMs = System.currentTimeMillis() - lastSyncOkAt.get();        if (staleMs > 60_000) {            return Health.down().withDetail("staleMs", staleMs).withDetail("reason", "库存缓存超过 60s 未同步").build();        }        return Health.up().withDetail("staleMs", staleMs).build();    }    public void markSynced() {        lastSyncOkAt.set(System.currentTimeMillis());    }}

# ① 索引页：确认暴露面只有四个curl -s http://localhost:9090/actuator# ② 健康总览（未授权，所以看不到 components）curl -s http://localhost:9090/actuator/health# ③ 分组探针地址curl -s http://localhost:9090/actuator/health/livenesscurl -s http://localhost:9090/actuator/health/readiness# ④ 业务端口上访问管理端点 → 应当 404curl -i -s http://localhost:8080/actuator/health | head -1# ⑤ 敏感端点应当 404curl -i -s http://localhost:9090/actuator/env | head -1# ⑥ 动态改日志级别，然后立刻观察curl -s -X POST http://localhost:9090/actuator/loggers/com.example.monitorlab \     -H "Content-Type: application/json" -d '{"configuredLevel":"DEBUG"}'curl -s http://localhost:9090/actuator/loggers/com.example.monitorlabcurl -s -X POST http://localhost:9090/actuator/loggers/com.example.monitorlab \     -H "Content-Type: application/json" -d '{"configuredLevel":null}'# ⑦ 指标下钻curl -s http://localhost:9090/actuator/metricscurl -s "http://localhost:9090/actuator/metrics/hikaricp.connections.pending"curl -s http://localhost:9090/actuator/prometheus | grep -E "^jvm_memory_used_bytes|^http_server_requests" | head -3

{ "status": "UP" }

{ "status": "UP", "group": "liveness" }

{ "status": "UP", "group": "readiness", "components": { "db": { "status": "UP" }, "diskSpace": { "status": "UP" } } }

HTTP/1.1 404HTTP/1.1 404