做自己的网站如何赚钱的,京东的网络营销方式,最佳的搜索引擎,重庆做网站个人本文是本系列的最后一篇。 看一下第1 部分和第2部分 。 在本系列的最后一篇文章中#xff0c;我将展示如何在JDK中使用本机JMX支持来实现一种通知机制#xff0c;该机制可以在HEAP内存超过特定阈值时向侦听器发出警报。 正如我在上一篇文章中讨论的那样#xff0c;这种方法… 本文是本系列的最后一篇。 看一下第1 部分和第2部分 。 在本系列的最后一篇文章中我将展示如何在JDK中使用本机JMX支持来实现一种通知机制该机制可以在HEAP内存超过特定阈值时向侦听器发出警报。 正如我在上一篇文章中讨论的那样这种方法是理想的因为它是推式而不是拉式不是侵入式的并且对应用程序的计算需求最小。 这些是本文说明的解决方案的关键组件 MemoryWarningService此组件充当侦听器并向Memory MBean注册其自身以接收通知。 可以使用介于0到1之间的百分比形式的阈值其中1为100进行配置 MemoryThreadDumper当通知MemoryWarningService HEAP使用量超过阈值并且其职责是将线程转储写入文件时将调用此组件。 MemoryWarningServiceConfigurator此组件是MBean它公开一种用于更改MemoryWarningService阈值的方法。 该解决方案还提供用于在测试应用程序时填充HEAP的MemoryHeapFiller类和用于引导Spring环境的MemTest类。 当应用程序运行时使用MemoryHeapFiller设置您可以在URL上触发JConsoleservicejmxrmi// localhost / jndi / rmi// localhost8888 / jemosJmxConnector以jemosAdmin / secure连接并更改阈值各种价值。 该代码不是用于生产的它不健壮缺少许多注释并且写入线程转储的文件名是硬编码的。 但是它代表了一个很好的起点。 该代码附在下面。 您将需要Maven来构建它。 下载Jemos-jmx-experiments-0.0.1-SNAPSHOT-project 我尝试了一个初始阈值为0.5的场景将其更改为0.3然后更改为0.8。 结果如下所示 2011-08-15 21:53:21 ClassPathXmlApplicationContext [INFO] Refreshing org.springframework.context.support.ClassPathXmlApplicationContexta4a63d8: startup date [Mon Aug 15 21:53:21 BST 2011]; root of context hierarchy
2011-08-15 21:53:21 XmlBeanDefinitionReader [INFO] Loading XML bean definitions from class path resource [jemos-jmx-appCtx.xml]
2011-08-15 21:53:21 PropertyPlaceholderConfigurer [INFO] Loading properties file from class path resource [jemos-jmx.properties]
2011-08-15 21:53:21 PropertyPlaceholderConfigurer [INFO] Loading properties file from URL [file:/C:/Users/mtedone/.secure/jmxconnector-credentials.properties]
2011-08-15 21:53:21 ThreadPoolTaskScheduler [INFO] Initializing ExecutorService myScheduler
2011-08-15 21:53:21 ClassPathXmlApplicationContext [INFO] Bean myScheduler of type [class org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2011-08-15 21:53:21 DefaultListableBeanFactory [INFO] Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory30296f76: defining beans [propertyConfigurer,loggerConfigurator,memoryWarningServiceConfigurator,memoryHeapFiller,memoryThreadDumper,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,mbeanExporter,jemosJmxServer,rmiRegistry,clientConnector,memoryMxBean,memoryWarningService,org.springframework.scheduling.annotation.internalAsyncAnnotationProcessor,org.springframework.scheduling.annotation.internalScheduledAnnotationProcessor,myScheduler]; root of factory hierarchy
2011-08-15 21:53:21 AnnotationMBeanExporter [INFO] Registering beans for JMX exposure on startup
2011-08-15 21:53:21 RmiRegistryFactoryBean [INFO] Looking for RMI registry at port 8888
2011-08-15 21:53:23 RmiRegistryFactoryBean [INFO] Could not detect RMI registry - creating new one
2011-08-15 21:53:23 ConnectorServerFactoryBean [INFO] JMX connector server started: javax.management.remote.rmi.RMIConnectorServer4355d3a3
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Bean with name jemosJmxServer has been autodetected for JMX exposure
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Bean with name loggerConfigurator has been autodetected for JMX exposure
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Bean with name memoryWarningServiceConfigurator has been autodetected for JMX exposure
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Located managed bean loggerConfigurator: registering with JMX server as MBean [jemos.mbeans:typeconfig,nameLoggingConfiguration]
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Located MBean jemosJmxServer: registering with JMX server as MBean [jemos.mbeans:namejemosJmxServer,typeRMIConnectorServer]
2011-08-15 21:53:23 AnnotationMBeanExporter [INFO] Located managed bean memoryWarningServiceConfigurator: registering with JMX server as MBean [jemos.mbeans:typeconfig,nameMemoryWarningServiceConfiguration]
2011-08-15 21:53:23 MemoryWarningService [INFO] Percentage is: 0.5
2011-08-15 21:53:23 MemoryWarningService [INFO] Listener added to JMX bean
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2011-08-15 21:53:37 MemoryWarningService [INFO] Percentage is: 0.3
2011-08-15 21:53:37 MemoryWarningServiceConfigurator [INFO] Memory threshold set to 0.3
Adding data...
2011-08-15 21:53:38 MemoryWarningService [WARN] Memory usage low!!!
2011-08-15 21:53:38 MemoryWarningService [WARN] percentageUsed 0.3815679398794023
2011-08-15 21:53:38 MemoryThreadDumper [WARN] Stacks dumped to: C:/tmp/stacks.dump
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2011-08-15 21:53:45 MemoryWarningService [INFO] Percentage is: 0.8
2011-08-15 21:53:45 MemoryWarningServiceConfigurator [INFO] Memory threshold set to 0.8
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2011-08-15 21:54:01 MemoryWarningService [WARN] Memory usage low!!!
2011-08-15 21:54:01 MemoryWarningService [WARN] percentageUsed 0.8383333266727508
2011-08-15 21:54:02 MemoryThreadDumper [WARN] Stacks dumped to: C:/tmp/stacks.dump
Adding data...
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Exception in thread JMX server connection timeout 24 java.lang.OutOfMemoryError: Java heap space 内存警告服务 package uk.co.jemos.experiments.jmx;import java.lang.management.ManagementFactory;
import java.lang.management.MemoryNotificationInfo;
import java.lang.management.MemoryPoolMXBean;
import java.lang.management.MemoryType;import javax.annotation.PostConstruct;
import javax.management.Notification;
import javax.management.NotificationEmitter;
import javax.management.NotificationListener;import org.springframework.beans.factory.annotation.Autowired;/*** A component which sends notifications when the HEAP memory is above a certain* threshold.* * author mtedone* */
public class MemoryWarningService implements NotificationListener {/** This beans name */public static final String MBEAN_NAME jemos.mbeans:typemonitoring,nameMemoryWarningService;/** The application logger */private static final org.apache.log4j.Logger LOG org.apache.log4j.Logger.getLogger(MemoryWarningService.class);Autowiredprivate NotificationEmitter memoryMxBean;Autowiredprivate MemoryThreadDumper threadDumper;/** A pool of Memory MX Beans specialised in HEAP management */private static final MemoryPoolMXBean tenuredGenPool findTenuredGenPool();/*** {inheritDoc}*/Overridepublic void handleNotification(Notification notification, Object handback) {if (notification.getType().equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED)) {long maxMemory tenuredGenPool.getUsage().getMax();long usedMemory tenuredGenPool.getUsage().getUsed();LOG.warn(Memory usage low!!!);double percentageUsed (double) usedMemory / maxMemory;LOG.warn(percentageUsed percentageUsed);threadDumper.dumpStacks();} else {LOG.info(Other notification received... notification.getMessage());}}/*** It sets the threshold percentage.* * param percentage*/public void setPercentageUsageThreshold(double percentage) {if (percentage 0.0 || percentage 1.0) {throw new IllegalArgumentException(Percentage not in range);} else {LOG.info(Percentage is: percentage);}long maxMemory tenuredGenPool.getUsage().getMax();long warningThreshold (long) (maxMemory * percentage);tenuredGenPool.setUsageThreshold(warningThreshold);}PostConstructpublic void completeSetup() {memoryMxBean.addNotificationListener(this, null, null);LOG.info(Listener added to JMX bean);}/*** Tenured Space Pool can be determined by it being of type HEAP and by it* being possible to set the usage threshold.*/private static MemoryPoolMXBean findTenuredGenPool() {for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {// I dont know whether this approach is better, or whether// we should rather check for the pool name Tenured Gen?if (pool.getType() MemoryType.HEAP pool.isUsageThresholdSupported()) {return pool;}}throw new AssertionError(Could not find tenured space);}} 内存线程转储器 package uk.co.jemos.experiments.jmx;import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;import org.apache.commons.io.IOUtils;
import org.springframework.stereotype.Component;/*** This component dumps the thread stack to the file system.* * author mtedone* */
Component
public class MemoryThreadDumper {/** The application logger */private static final org.apache.log4j.Logger LOG org.apache.log4j.Logger.getLogger(MemoryThreadDumper.class);/*** It dumps the Thread stacks* * throws IOException*/public void dumpStacks() {// hard-coded: This needs to be changed to a property or somethingString stackFileName C:/tmp/stacks.dump;ThreadMXBean mxBean ManagementFactory.getThreadMXBean();ThreadInfo[] threadInfos mxBean.getThreadInfo(mxBean.getAllThreadIds(), 0);MapLong, ThreadInfo threadInfoMap new HashMapLong, ThreadInfo();for (ThreadInfo threadInfo : threadInfos) {threadInfoMap.put(threadInfo.getThreadId(), threadInfo);}File dumpFile new File(stackFileName);BufferedWriter writer null;try {writer new BufferedWriter(new FileWriter(dumpFile));this.dumpTraces(mxBean, threadInfoMap, writer);LOG.warn(Stacks dumped to: stackFileName);} catch (IOException e) {throw new IllegalStateException(An exception occurred while writing the thread dump);} finally {IOUtils.closeQuietly(writer);}}private void dumpTraces(ThreadMXBean mxBean,MapLong, ThreadInfo threadInfoMap, Writer writer)throws IOException {MapThread, StackTraceElement[] stacks Thread.getAllStackTraces();writer.write(Dump of stacks.size() thread at new SimpleDateFormat(yyyy/MM/dd HH:mm:ss z).format(new Date(System.currentTimeMillis())) \n\n);for (Map.EntryThread, StackTraceElement[] entry : stacks.entrySet()) {Thread thread entry.getKey();writer.write(\ thread.getName() \ prio thread.getPriority() tid thread.getId() thread.getState() (thread.isDaemon() ? deamon : worker) \n);ThreadInfo threadInfo threadInfoMap.get(thread.getId());if (threadInfo ! null) {writer.write( native threadInfo.isInNative() , suspended threadInfo.isSuspended() , block threadInfo.getBlockedCount() , wait threadInfo.getWaitedCount() \n);writer.write( lock threadInfo.getLockName() owned by threadInfo.getLockOwnerName() ( threadInfo.getLockOwnerId() ), cpu mxBean.getThreadCpuTime(threadInfo.getThreadId())/ 1000000L , user mxBean.getThreadUserTime(threadInfo.getThreadId())/ 1000000L \n);}for (StackTraceElement element : entry.getValue()) {writer.write( );writer.write(element.toString());writer.write(\n);}writer.write(\n);}}} 内存服务配置MBean package uk.co.jemos.experiments.jmx.mbeans;import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.jmx.export.annotation.ManagedOperation;
import org.springframework.jmx.export.annotation.ManagedOperationParameter;
import org.springframework.jmx.export.annotation.ManagedOperationParameters;
import org.springframework.jmx.export.annotation.ManagedResource;
import org.springframework.stereotype.Component;import uk.co.jemos.experiments.jmx.MemoryWarningService;Component
ManagedResource(objectName MemoryWarningServiceConfigurator.MBEAN_NAME, //
description Allows clients to set the memory threshold)
public class MemoryWarningServiceConfigurator implementsApplicationContextAware {/** The application logger */private static final org.apache.log4j.Logger LOG org.apache.log4j.Logger.getLogger(MemoryWarningServiceConfigurator.class);public static final String MBEAN_NAME jemos.mbeans:typeconfig,nameMemoryWarningServiceConfiguration;private ApplicationContext ctx;ManagedOperation(description Sets the memory threshold for the memory warning system)ManagedOperationParameters({ ManagedOperationParameter(description The memory threshold, name memoryThreshold), })public void setMemoryThreshold(double memoryThreshold) {MemoryWarningService memoryWarningService (MemoryWarningService) ctx.getBean(memoryWarningService);memoryWarningService.setPercentageUsageThreshold(memoryThreshold);LOG.info(Memory threshold set to memoryThreshold);}Overridepublic void setApplicationContext(ApplicationContext applicationContext)throws BeansException {ctx applicationContext;}} Spring配置 ?xml version1.0 encodingUTF-8?
beans xmlnshttp://www.springframework.org/schema/beansxmlns:xsihttp://www.w3.org/2001/XMLSchema-instance xmlns:contexthttp://www.springframework.org/schema/contextxmlns:utilhttp://www.springframework.org/schema/utilxmlns:taskhttp://www.springframework.org/schema/taskxsi:schemaLocationhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsdhttp://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsdhttp://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsdbean idpropertyConfigurer classorg.springframework.beans.factory.config.PropertyPlaceholderConfigurer property namelocationslistvalueclasspath:jemos-jmx.properties/valuevaluefile:///${user.home}/.secure/jmxconnector-credentials.properties/value/list/property/beancontext:component-scan base-packageuk.co.jemos.experiments.jmx /context:mbean-export default-domainjemos.mbeans /bean idjemosJmxServer classorg.springframework.jmx.support.ConnectorServerFactoryBean depends-onrmiRegistryproperty nameobjectName valueconnector:namermi /property nameserviceUrlvalueservice:jmx:rmi://localhost/jndi/rmi://localhost:${jemos.jmx.rmi.port}/jemosJmxConnector /property nameenvironment!-- the following is only valid when the sun jmx implementation is used --mapentry keyjmx.remote.x.password.file value${user.home}/.secure/jmxremote.password /entry keyjmx.remote.x.access.file value${user.home}/.secure/jmxremote.access //map/property/beanbean idrmiRegistry classorg.springframework.remoting.rmi.RmiRegistryFactoryBeanproperty nameport value${jemos.jmx.rmi.port} //beanbean idclientConnector classorg.springframework.jmx.support.MBeanServerConnectionFactoryBean depends-onjemosJmxServerproperty nameserviceUrlvalueservice:jmx:rmi://localhost/jndi/rmi://localhost:${jemos.jmx.rmi.port}/jemosJmxConnector /property nameenvironmentmapentry keyjmx.remote.credentialsbeanfactory-methodcommaDelimitedListToStringArrayconstructor-arg value${jmx.username},${jmx.password} //bean/entry/map/property/beanbean idmemoryMxBean classjava.lang.management.ManagementFactoryfactory-methodgetMemoryMXBean /bean idmemoryWarningService classuk.co.jemos.experiments.jmx.MemoryWarningServiceproperty namepercentageUsageThreshold value0.5 //beantask:annotation-driven schedulermyScheduler / task:scheduler idmyScheduler pool-size10 / /beans 参考 JMX和Spring –我们的JCG合作伙伴 Marco Tedone的第3部分 位于Marco Tedone的博客博客中。 翻译自: https://www.javacodegeeks.com/2012/07/jmx-and-spring-part-3.html
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