应用没有监控,没有画板,一切指标都没有。在这个Growth Hack逐渐成为主流的时代,不弄个Dashboard把系统压力、QPS、CPU、内存、日活啥的可视化,你好意思出来混吗……
本节我们来解决该问题。 Spring Boot Actuator是Spring Boot官方提供的监控组件。只需为项目添加以下依赖,即可就整合Spring Boot Actuator。
- <dependency>
- <groupId>org.springframework.boot</groupId>
- <artifactId>spring-boot-starter-actuator</artifactId>
- </dependency>
监控端点
Actuator为我们提供了很多监控端点,如下表所示。
[td]
端点(Spring Boot 2.x) | 描述 | HTTP方法 | 是否敏感 | 端点(Spring Boot 1.x) |
conditions | 显示自动配置的信息 | GET | 是 | autoconfig |
beans | 显示应用程序上下文所有的Spring bean | GET | 是 | beans |
configprops | 显示所有@ConfigurationProperties 的配置属性列表 | GET | 是 | configprops |
dump | 显示线程活动的快照 | GET | 是 | dump |
env | 显示环境变量,包括系统环境变量 以及应用环境变量 | GET | 是 | env |
health | 显示应用程序的健康指标,值由 HealthIndicator的实现类提供;结果有UP、 DOWN、OUTOFSERVICE、UNKNOWN ,如需查看看详情,需配置: management.endpoint.health.show-details | GET | 否 | health |
info | 显示应用的信息,可使用 info.*属性自定义info端点公开的数据 | GET | 否 | info |
mappings | 显示所有的URL路径 | GET | 是 | mappings |
metrics | 显示应用的度量标准信息 | GET | 是 | metrics |
表-Spring Boot Actuator常用端点及描述 只需访问 http://{ip}:{port}/actuator/{endpoint} 端点,即可监控应用的运行状况。
测试1:/health端点
为前文编写的 microservice-simple-provider-user 服务整合Actuator后,我们来做一些测试: 访问http://localhost:8000/actuator/health ,即可获得如下结果:
- {"status":"UP"}
测试2:/health端点展示详情
为 /health 端点配置显示详情:
- management:
- endpoint:
- health:
- # 是否展示健康检查详情
- show-details: always
再次访问http://localhost:8000/actuator/health ,即可获得如下结果:
- {
- "status": "UP",
- "details": {
- "db": {
- "status": "UP",
- "details": {
- "database": "H2",
- "hello": 1
- }
- },
- "diskSpace": {
- "status": "UP",
- "details": {
- "total": 250790436864,
- "free": 43443773440,
- "threshold": 10485760
- }
- }
- }
- }
从中可以看到, /health 端点展示了DB的健康情况以及磁盘的健康情况。
测试3:暴露敏感路径
默认情况下,敏感路径并不暴露。如需暴露(以metrics为例),需添加配置:
- management:
- endpoints:
- web:
- exposure:
- # 暴露metrics端点,如需暴露多个,用,分隔;如需暴露所有端点,用'*'
- include: metrics
访问:http://localhost:8000/actuator/metrics ,可获得类似如下的结果:
- {
- "names": ["jvm.memory.max", "http.server.requests", "jdbc.connections.active", "process.files.max", "jvm.gc.memory.promoted", "tomcat.cache.hit", "system.load.average.1m", "tomcat.cache.access", "jvm.memory.used", "jvm.gc.max.data.size", "jdbc.connections.max", "jdbc.connections.min", "jvm.gc.pause", "jvm.memory.committed", "system.cpu.count", "logback.events", "tomcat.global.sent", "jvm.buffer.memory.used", "tomcat.sessions.created", "jvm.threads.daemon", "system.cpu.usage", "jvm.gc.memory.allocated", "tomcat.global.request.max", "hikaricp.connections.idle", "hikaricp.connections.pending", "tomcat.global.request", "tomcat.sessions.expired", "hikaricp.connections", "jvm.threads.live", "jvm.threads.peak", "tomcat.global.received", "hikaricp.connections.active", "hikaricp.connections.creation", "process.uptime", "tomcat.sessions.rejected", "process.cpu.usage", "tomcat.threads.config.max", "jvm.classes.loaded", "hikaricp.connections.max", "hikaricp.connections.min", "jvm.classes.unloaded", "tomcat.global.error", "tomcat.sessions.active.current", "tomcat.sessions.alive.max", "jvm.gc.live.data.size", "tomcat.servlet.request.max", "hikaricp.connections.usage", "tomcat.threads.current", "tomcat.servlet.request", "hikaricp.connections.timeout", "process.files.open", "jvm.buffer.count", "jvm.buffer.total.capacity", "tomcat.sessions.active.max", "hikaricp.connections.acquire", "tomcat.threads.busy", "process.start.time", "tomcat.servlet.error"]
- }
访问http://localhost:8000/actuator/metrics/{name} , {name} 列表如上,即可查看当前应用的度量指标。例如访问:http://localhost:8000/actuator/metrics/jvm.memory.max 即可查看JVM可管理的最大内存,结果类似如下:
- {
- "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": 5.597298687E9
- }],
- "availableTags": [{
- "tag": "area",
- "values": ["heap", "nonheap"]
- }, {
- "tag": "id",
- "values": ["Compressed Class Space", "PS Survivor Space", "PS Old Gen", "Metaspace", "PS Eden Space", "Code Cache"]
- }
TIPS
1 如需暴露所有监控端点可配置:
- management:
- endpoints:
- web:
- exposure:
- include: '*'
2 有关Spring Boot 1.x与2.x端点的差异,详见:https://github.com/spring-projec ... ion-Guide#endpoints
拓展阅读
如果能对Actuator端点的文字数据进行图形化的展示,我们就可以实现比较低层次的“Growth Hack”啦!开源界已经有这样的工具—— SpringBootAdmin ,界面如下。有兴趣的可前往https://github.com/codecentric/spring-boot-admin了解。 <ignore_js_op>
说明
- 由于Actuator本身是Spring Boot中的组件,并不是本套教程的重点(其实笔者本不想写这一节,但后面又会持续用这些端点,并且Spring Cloud在这些端点的基础上还做了一些增加,所以还是有必要介绍一下),因此本节只是对Actuator进行了比较简单的介绍,读者可自行挖掘Actuator的其他能力。也可持续关注本公众号,本系列完成后,笔者将会扒开Actuator的底裤,深度介绍Spring Boot监控的那些事儿。