可观测性 Observability
对线上应用进行观测、监控、预警...
健康状况【组件状态、存活状态】Health
运行指标【cpu、内存、垃圾回收、吞吐量、响应成功率...】Metrics
链路追踪
...
1. SpringBoot Actuator
1. 实战
1. 场景引入
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>2. 暴露指标
management:
endpoints:
enabled-by-default: true #暴露所有端点信息
web:
exposure:
include: '*' #以web方式暴露3. 访问数据
访问 http://localhost:8080/actuator；展示出所有可以用的监控端点
http://localhost:8080/actuator/endpointName/detailPath
2. Endpoint
1. 常用端点
threaddump、heapdump、metrics
2. 定制端点
健康监控：返回存活、死亡
指标监控：次数、率
1. HealthEndpoint
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
@Component
public class MyHealthIndicator implements HealthIndicator {
@Override
public Health health() {
int errorCode = check(); // perform some specific health check
if (errorCode != 0) {
return Health.down().withDetail("Error Code", errorCode).build();
}
return Health.up().build();
}
}
构建Health
Health build = Health.down()
.withDetail("msg", "error service")
.withDetail("code", "500")
.withException(new RuntimeException())
.build();management:
health:
enabled: true
show-details: always #总是显示详细信息。可显示每个模块的状态信息@Component
public class MyComHealthIndicator extends AbstractHealthIndicator {
/**
* 真实的检查方法
* @param builder
* @throws Exception
*/
@Override
protected void doHealthCheck(Health.Builder builder) throws Exception {
//mongodb。 获取连接进行测试
Map<String,Object> map = new HashMap<>();
// 检查完成
if(1 == 2){
// builder.up(); //健康
builder.status(Status.UP);
map.put("count",1);
map.put("ms",100);
}else {
// builder.down();
builder.status(Status.OUT_OF_SERVICE);
map.put("err","连接超时");
map.put("ms",3000);
}
builder.withDetail("code",100)
.withDetails(map);
}
}2. MetricsEndpoint
class MyService{
Counter counter;
public MyService(MeterRegistry meterRegistry){
counter = meterRegistry.counter("myservice.method.running.counter");
}
public void hello() {
counter.increment();
}
}
2. 监控案例落地
基于 Prometheus + Grafana
1. 安装 Prometheus + Grafana
#安装prometheus:时序数据库
docker run -p 9090:9090 -d \
-v pc:/etc/prometheus \
prom/prometheus
#安装grafana；默认账号密码 admin:admin
docker run -d --name=grafana -p 3000:3000 grafana/grafana2. 导入依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>io.micrometer</groupId>
<artifactId>micrometer-registry-prometheus</artifactId>
<version>1.10.6</version>
</dependency>management:
endpoints:
web:
exposure: #暴露所有监控的端点
include: '*'访问： http://localhost:8001/actuator/prometheus 验证，返回 prometheus 格式的所有指标
部署Java应用
#安装上传工具
yum install lrzsz
#安装openjdk
# 下载openjdk
wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.tar.gz
mkdir -p /opt/java
tar -xzf jdk-17_linux-x64_bin.tar.gz -C /opt/java/
sudo vi /etc/profile
#加入以下内容
export JAVA_HOME=/opt/java/jdk-17.0.7
export PATH=$PATH:$JAVA_HOME/bin
#环境变量生效
source /etc/profile
# 后台启动java应用
nohup java -jar boot3-14-actuator-0.0.1-SNAPSHOT.jar > output.log 2>&1 &
确认可以访问到： http://8.130.32.70:9999/actuator/prometheus
3. 配置 Prometheus 拉取数据
## 修改 prometheus.yml 配置文件
scrape_configs:
- job_name: 'spring-boot-actuator-exporter'
metrics_path: '/actuator/prometheus' #指定抓取的路径
static_configs:
- targets: ['192.168.200.1:8001']
labels:
nodename: 'app-demo'4. 配置 Grafana 监控面板
添加数据源（Prometheus）
添加面板。可去 dashboard 市场找一个自己喜欢的面板，也可以自己开发面板;Dashboards | Grafana Labs
5. 效果
