spring boot的actuator

actuator官方的介绍

Spring Boot includes a number of additional features to help you monitor and manage your application when it’s pushed to production. You can choose to manage and monitor your application using HTTP endpoints, with JMX or even by remote shell (SSH or Telnet). Auditing, health and metrics gathering can be automatically applied to your application.

actuator是一个强大功能，有助于对应用程序进行监视和管理，通过restful api请求来监管、审计、收集应用的运行情况

1.添加依赖

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

2.启动项目

用浏览器打开 http://localhost:8080/actuator

{
    "_links": {
        "self": {
            "href": "http://localhost:8080/actuator",
            "templated": false
        },
        "health": {
            "href": "http://localhost:8080/actuator/health",
            "templated": false
        },
        "health-component": {
            "href": "http://localhost:8080/actuator/health/{component}",
            "templated": true
        },
        "health-component-instance": {
            "href": "http://localhost:8080/actuator/health/{component}/{instance}",
            "templated": true
        },
        "info": {
            "href": "http://localhost:8080/actuator/info",
            "templated": false
        }
    }
}

actuator暴露了三个简单的endpoint

开启所有接口，在application.properties中，添加

management.endpoints.web.exposure.include=*

刷新 http://localhost:8080/actuator页面，会出现很多endpoint

{
    "_links": {
        "self": {
            "href": "http://localhost:8080/actuator",
            "templated": false
        },
        "auditevents": {
            "href": "http://localhost:8080/actuator/auditevents",
            "templated": false
        },
        "beans": {
            "href": "http://localhost:8080/actuator/beans",
            "templated": false
        },
        "caches-cache": {
            "href": "http://localhost:8080/actuator/caches/{cache}",
            "templated": true
        },
        "caches": {
            "href": "http://localhost:8080/actuator/caches",
            "templated": false
        },
        "health-component": {
            "href": "http://localhost:8080/actuator/health/{component}",
            "templated": true
        },
        "health-component-instance": {
            "href": "http://localhost:8080/actuator/health/{component}/{instance}",
            "templated": true
        },
        "health": {
            "href": "http://localhost:8080/actuator/health",
            "templated": false
        },
        ……
    }
}

（1）/actuator/health 查看应用健康指标

{
    "status": "UP"
}

（2）/actuator/info查看应用的定制信息

　　在配置文件中以 info 开头的配置信息

application.properties包含

info.app.name=abc
info.app.version=1.0.0

返回结果

{
    "app": {
        "name": "abc",
        "version": "1.0.0"
    }
}

（3）/actuator/metrics 查看应用基本指标

　　返回actuator提供的所有metric的name

　　/actuator/metrics/{name}查看具体指标

　　使用 /actuator/metrics/jvm.memory.max，查看JVM最大内存

{
    "name": "jvm.memory.max",
    "description": "The maximum amount of memory in bytes that can be used for memory management",
    "baseUnit": "bytes",
    "measurements": [
        {
            "statistic": "VALUE",
            "value": 5.583142911E9
        }
    ],
    "availableTags": [
        {
            "tag": "area",
            "values": [
                "heap",
                "nonheap"
            ]
        },
        {
            "tag": "id",
            "values": [
                "Compressed Class Space",
                "PS Survivor Space",
                "PS Old Gen",
                "Metaspace",
                "PS Eden Space",
                "Code Cache"
            ]
        }
    ]
}

（4）/actuator/beans 应用中所有Spring Beans的完整列表

    "contexts": {
        "application": {
            "beans": {
                "spring.jpa-org.springframework.boot.autoconfigure.orm.jpa.JpaProperties": {
                    "aliases": [],
                    "scope": "singleton",
                    "type": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties",
                    "resource": null,
                    "dependencies": []
                },"uploadController": {
                    "aliases": [],
                    "scope": "singleton",
                    "type": "com.example.demo.controller.UploadController$$EnhancerBySpringCGLIB$$b6fa2feb",
                    "resource": "file [E:\\java\\demo\\target\\classes\\com\\example\\demo\\controller\\UploadController.class]",
                    "dependencies": []
                },
                ……
            },
            "parentId": null
        }
    }
}

（5）/actuator/heapdump dump 一份应用的 JVM 堆信息

　　可以使用 JDK 自带的 Jvm 监控工具 VisualVM 打开该文件查看内存快照

（6）/actuator/scheduledtasks 应用中的定时任务信息

（7）/actuator/env 获取全部环境属性

　　/actuator/env/{name} 获取特定的环境属性值

　　/actuator/env/java.version java版本

{
    "property": {
        "source": "systemProperties",
        "value": "1.8.0_151"
    },
    "activeProfiles": [
        "dev"
    ],
    "propertySources": [
        {
            "name": "server.ports"
        },
        {
            "name": "servletConfigInitParams"
        },
        {
            "name": "servletContextInitParams"
        },
        {
            "name": "systemProperties",
            "property": {
                "value": "1.8.0_151"
            }
        },
        {
            "name": "systemEnvironment"
        },
        {
            "name": "random"
        },
        {
            "name": "applicationConfig: [classpath:/application.properties]"
        },
        {
            "name": "Management Server"
        }
    ]
}