Spring Boot Actuator幫助我們實現了許多中間件比如mysql、es、redis、mq等中間件的健康指示器。
通過 Spring Boot 的自動配置,這些指示器會自動生效。當這些組件有問題的時候,HealthIndicator 會返回 DOWN 或 OUT_OF_SERVICE 狀態,health 端點 HTTP 響應狀態碼也會變為 503,我們可以以此來配置程序健康狀態監控報警。
使用步驟也非常簡單,這裡演示的是線程池的監控。模擬線程池滿了狀態下將HealthInicator指示器變為Down的狀態。
pom中引入jar
org.springframework.bootspring-boot-starter-actuator
引入properties配置
spring.application.name=boot # server.servlet.context-path=/boot # management.server.servlet.context-path=/boot # JVM (Micrometer)要求給應用設置commonTag management.metrics.tags.application=${spring.application.name} #去掉重複的metrics spring.metrics.servo.enabled=false management.endpoint.metrics.enabled=true management.endpoint.metrics.sensitive=false #顯式配置不需要權限驗證對外開放的端點 management.endpoints.web.exposure.include=* management.endpoints.jmx.exposure.include=* management.endpoint.health.show-details=always #Actuator 的 Web 訪問方式的根地址為 /actuator,可以通過 management.endpoints.web.base-path 參數進行修改 management.endpoints.web.base-path=/actuator management.metrics.export.prometheus.enabled=true
代碼
/** * @Author jeffSmile * @Date 下午 6:10 2020/5/24 0024 * @Description 定義一個接口,來把耗時很長的任務提交到這個 demoThreadPool 線程池,以模擬線程池隊列滿的情況 **/ @GetMapping("slowTask") public void slowTask() { ThreadPoolProvider.getDemoThreadPool().execute(() -> { try { TimeUnit.HOURS.sleep(1); } catch (InterruptedException e) { } }); }
package com.mongo.boot.service; import jodd.util.concurrent.ThreadFactoryBuilder; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; public class ThreadPoolProvider { //一個工作線程的線程池,隊列長度10 private static ThreadPoolExecutor demoThreadPool = new ThreadPoolExecutor( 1, 1, 2, TimeUnit.SECONDS, new ArrayBlockingQueue<>(10), new ThreadFactoryBuilder().setNameFormat("demo-threadpool-%d").get()); //核心線程數10,最大線程數50的線程池,隊列長度50 private static ThreadPoolExecutor ioThreadPool = new ThreadPoolExecutor( 10, 50, 2, TimeUnit.SECONDS, new ArrayBlockingQueue<>(100), new ThreadFactoryBuilder().setNameFormat("io-threadpool-%d").get()); public static ThreadPoolExecutor getDemoThreadPool() { return demoThreadPool; } public static ThreadPoolExecutor getIOThreadPool() { return ioThreadPool; } }
package com.mongo.boot.service; import org.springframework.boot.actuate.health.Health; import org.springframework.boot.actuate.health.HealthIndicator; import java.util.HashMap; import java.util.Map; import java.util.concurrent.ThreadPoolExecutor; /** * @Author jeffSmile * @Date 下午 6:12 2020/5/24 0024 * @Description 自定義的 HealthIndicator 類,用於單一線程池的健康狀態 **/ public class ThreadPoolHealthIndicator implements HealthIndicator { private ThreadPoolExecutor threadPool; public ThreadPoolHealthIndicator(ThreadPoolExecutor threadPool) { this.threadPool = threadPool; } @Override public Health health() { //補充信息 Mapdetail = new HashMap<>(); //隊列當前元素個數 detail.put("queue_size", threadPool.getQueue().size()); //隊列剩餘容量 detail.put("queue_remaining", threadPool.getQueue().remainingCapacity()); //如果還有剩餘量則返回UP,否則返回DOWN if (threadPool.getQueue().remainingCapacity() > 0) { return Health.up().withDetails(detail).build(); } else { return Health.down().withDetails(detail).build(); } } }
package com.mongo.boot.service; import org.springframework.boot.actuate.health.CompositeHealthContributor; import org.springframework.boot.actuate.health.HealthContributor; import org.springframework.boot.actuate.health.NamedContributor; import org.springframework.stereotype.Component; import java.util.HashMap; import java.util.Iterator; import java.util.Map; /*** * @Author jeffSmile * @Date 下午 6:13 2020/5/24 0024 * @Description 定義一個 CompositeHealthContributor,來聚合兩個 ThreadPoolHealthIndicator 的實例, * 分別對應 ThreadPoolProvider 中定義的兩個線程池 **/ @Component public class ThreadPoolsHealthContributor implements CompositeHealthContributor { //保存所有的子HealthContributor private Mapcontributors = new HashMap<>(); ThreadPoolsHealthContributor() { //對應ThreadPoolProvider中定義的兩個線程池 this.contributors.put("demoThreadPool", new ThreadPoolHealthIndicator(ThreadPoolProvider.getDemoThreadPool())); this.contributors.put("ioThreadPool", new ThreadPoolHealthIndicator(ThreadPoolProvider.getIOThreadPool())); } @Override public HealthContributor getContributor(String name) { //根據name找到某一個HealthContributor return contributors.get(name); } @Override public Iterator<NamedContributor> iterator() { //返回NamedContributor的迭代器,NamedContributor也就是Contributor實例+一個命名 return contributors.entrySet().stream() .map((entry) -> NamedContributor.of(entry.getKey(), entry.getValue())).iterator(); } }
啟動springboot驗證
這裡我訪問:http://localhost:8080/slowTask
每次訪問都向demo線程池中提交一個耗時1小時的任務,而demo線程池的核心和最大線程數都是1,隊列長度為10,那麼當訪問11次之後,任務將被直接拒絕掉!
此時訪問:http://localhost:8080/actuator/health
demo線程池隊列已經滿了,狀態變為DOWN。
監控內部重要組件的狀態數據
通過 Actuator 的 InfoContributor 功能,對外暴露程序內部重要組件的狀態數據!
實現一個 ThreadPoolInfoContributor 來展現線程池的信息:
package com.mongo.boot.config; import com.mongo.boot.service.ThreadPoolProvider; import org.springframework.boot.actuate.info.Info; import org.springframework.boot.actuate.info.InfoContributor; import org.springframework.stereotype.Component; import java.util.HashMap; import java.util.Map; import java.util.concurrent.ThreadPoolExecutor; /** * @Author jeffSmile * @Date 下午 6:37 2020/5/24 0024 * @Description 通過 Actuator 的 InfoContributor 功能,對外暴露程序內部重要組件的狀態數據 **/ @Component public class ThreadPoolInfoContributor implements InfoContributor { private static Map threadPoolInfo(ThreadPoolExecutor threadPool) { Mapinfo = new HashMap<>(); info.put("poolSize", threadPool.getPoolSize());//當前池大小 info.put("corePoolSize", threadPool.getCorePoolSize());//設置的核心池大小 info.put("largestPoolSize", threadPool.getLargestPoolSize());//最大達到過的池大小 info.put("maximumPoolSize", threadPool.getMaximumPoolSize());//設置的最大池大小 info.put("completedTaskCount", threadPool.getCompletedTaskCount());//總完成任務數 return info; } @Override public void contribute(Info.Builder builder) { builder.withDetail("demoThreadPool", threadPoolInfo(ThreadPoolProvider.getDemoThreadPool())); builder.withDetail("ioThreadPool", threadPoolInfo(ThreadPoolProvider.getIOThreadPool())); } }
直接訪問http://localhost:8080/actuator/info
如果開啟jmx,還可以使用jconsole來查看線程池的狀態信息:
#開啟 JMX spring.jmx.enabled=true
打開jconcole界面之後,進入MBean這個tab,可以在EndPoint下的Info操作這裡看到我們的Bean信息。
不過,除了jconsole之外,我們可以把JMX協議轉為http協議,這裡引入jolokia:
org.jolokiajolokia-core
重啟後訪問:http://localhost:8080/actuator/jolokia/exec/org.springframework.boot:type=Endpoint,name=Info/info
監控延伸
通過Micrometer+promethues+grafana的組合也可以進行一些生產級別的實踐。
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