标签：restart desc max tool reason report isp exp 发布
actuator 通过暴露一系列的endpoints可以让开发者快速了解spring boot的各项运行指标，比如：线程数，jvm剩余内存等一系列参数。
启用方法很简单，参考下面：
dependencies {
compile(‘org.springframework.boot:spring-boot-starter-thymeleaf‘)
compile(‘org.springframework.boot:spring-boot-devtools‘)
compile(‘org.springframework.boot:spring-boot-starter-actuator‘)
compile(‘org.springframework.boot:spring-boot-starter-test‘)
compileOnly(‘org.projectlombok:lombok‘)
}
关键是添加spring-boot-starter-actuator依赖项即可，下表是actuator提供的endpoints列表(从官网文档上抄过来的）
| ID | Description | Sensitive Default |
|---|---|---|
|
|
Provides a hypermedia-based “discovery page” for the other endpoints.Requires Spring HATEOAS to be on the classpath. |
true |
|
|
Exposes audit events information for the current application. |
true |
|
|
Displays an auto-configuration report showing all auto-configuration candidates and the reason why they ‘were’ or ‘were not’ applied. |
true |
|
|
Displays a complete list of all the Spring beans in your application. |
true |
|
|
Displays a collated list of all |
true |
|
|
Performs a thread dump. |
true |
|
|
Exposes properties from Spring’s |
true |
|
|
Shows any Flyway database migrations that have been applied. |
true |
|
|
Shows application health information (when the application is secure, a simple ‘status’ when accessed over an unauthenticated connection or full message details when authenticated). |
false |
|
|
Displays arbitrary application info. |
false |
|
|
Shows and modifies the configuration of loggers in the application. |
true |
|
|
Shows any Liquibase database migrations that have been applied. |
true |
|
|
Shows ‘metrics’ information for the current application. |
true |
|
|
Displays a collated list of all |
true |
|
|
Allows the application to be gracefully shutdown (not enabled by default). |
true |
|
|
Displays trace information (by default the last 100 HTTP requests). |
true |
这张表中，有很多信息其实是敏感信息，并不适合匿名访问（特别是在公网环境下），所以默认情况下，如果想访问类似 http://localhost:8081/metrics 会看到以下错误：
比较好的做法是，将这些endpoints的端口，包括访问路径与常规应用的端口分开，application.yml可以参考下面的配置:
server:
port: 8081
spring:
main:
banner-mode: "off"
devtools:
restart:
trigger-file: .trigger
thymeleaf:
cache: false
management:
security:
enabled: false #关掉安全认证
port: 1101 #管理端口调整成1101
context-path: /admin #actuator的访问路径
如果在公网环境，建议在防火墙上做下限制，仅允许8081进来，1101用于内网访问即可，这样相对比较安全，也不用繁琐的输入密码。
访问下http://localhost:1101/admin/metrics 可以看到类似以下输出：
{
mem: 466881,
mem.free: 289887,
processors: 4,
instance.uptime: 10947,
uptime: 18135,
systemload.average: 3.12646484375,
heap.committed: 411648,
heap.init: 131072,
heap.used: 121760,
heap: 1864192,
nonheap.committed: 56192,
nonheap.init: 2496,
nonheap.used: 55234,
nonheap: 0,
threads.peak: 27,
threads.daemon: 19,
threads.totalStarted: 32,
threads: 22,
classes: 6755,
classes.loaded: 6755,
classes.unloaded: 0,
gc.ps_scavenge.count: 8,
gc.ps_scavenge.time: 136,
gc.ps_marksweep.count: 2,
gc.ps_marksweep.time: 193,
httpsessions.max: -1,
httpsessions.active: 0
}
jvm的内存，cpu核数，线程数，gc情况一目了然，再结合其它一些工具把这些信息采集到grafana里，就有得到一系列很实用的监控图表数据，比如： 
其它endpoint，就不一一展示了，大家有兴趣可以自行研究，最后要提一下的是shutdown这个endpoint，它可以实现优雅停机，这在线上部署时很有用，发布前先调用这个url，让应用优雅停掉，再部署新的代码，这样就不会导致正在处理的请求被中断，不过默认该功能是关闭的，可参考下面的设置启用：
endpoints:
shutdown:
enabled: true
而且出于安全考虑，该url只能以post方式访问，下图是用postman模拟post访问 http://locahost:1101/admin/shutdown的效果：
同时在日志里也能看到应用确实被关闭：
参考文章：
http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready
标签：restart desc max tool reason report isp exp 发布
原文地址：http://www.cnblogs.com/yjmyzz/p/spring-boot-actuator-tutorial.html
