使用JMX监控Tomcat（监控应用服务器系列文章）

前言：做了一个监控应用服务器的项目（支持Tocmat、WebSphere、WebLogic各版本）， 过程也算是磕磕绊绊，由于网上缺少相关资料，或者深陷于知识的海洋难以寻觅到有效的资料，因而走过不少弯路，遇过不少困难。为了留下点印记，给后来人留下 点经验之谈，助之少走弯路，故将这些经验整理出来，与大家分享。水平有限，难免疏漏，还望指正。如有疑问，欢迎留言，或者加入Q群参与讨 论：35526521。

 

一、激活Tomcat的JMX远程配置

 

要通过JMX远程监控Tomcat，首先需要激活Tomcat的JMX远程配置。

 

① 先修改Tomcat的启动脚本，windows下为bin/catalina.bat（linux下为catalina.sh），添加以下内容，8999是jmxremote使用的端口号，第二个false表示不需要鉴权：

set JMX_REMOTE_CONFIG=-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false
set CATALINA_OPTS=%CATALINA_OPTS% %JMX_REMOTE_CONFIG%

 

要注意以上语句的位置不能太后面，可以加在【if "%OS%" == "Windows_NT" setlocal】一句后的大段的注释后面。

 

参考官方说明：
http://tomcat.apache.org/tomcat-6.0-doc/monitoring.html#Enabling_JMX_Remote

 

 

② 上面的配置是不需要鉴权的，如果需要鉴权则添加的内容为：

set JMX_REMOTE_CONFIG=-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=true -Dcom.sun.management.jmxremote.password.file=../conf/jmxremote.password -Dcom.sun.management.jmxremote.access.file=../conf/jmxremote.access
set CATALINA_OPTS=%CATALINA_OPTS% %JMX_REMOTE_CONFIG%

 

③ 然后复制并修改授权文件
$JAVA_HOME/jre/lib/management下有jmxremote.access和jmxremote.password的模板文件，将两个文件复制到$CATALINA_BASE/conf目录下

◆ 修改$CATALINA_BASE/conf/jmxremote.access 添加内容：
     monitorRole readonly
     controlRole readwrite
◆ 修改$CATALINA_BASE/conf/jmxremote.password 添加内容：
     monitorRole chenfeng
     controlRole chenfeng

 

 

注意： 如果进行了以上步骤导致Tomcat启动不了，那么很可能是密码文件的权限问题

需要修改jmxremote.password文件的访问权限，只有运行Tomcat的用户才能拥有访问权限 ：
      Windows的NTFS文件系统下，选中文件，点右键 -->“属性”-->“安全”--> 点“高级”--> 点“更改权限”--> 去掉“从父项继承....”--> 弹出窗口中选“删除”，这样就删除了所有访问权限。再选“添加”--> “高级”--> “立即查找”，选中你的用户（或用户组，如果选用户不行那就选用户组），例administrator，点“确定"，“确定"。来到权限项目窗口，勾选“完全控制”，点“确定”，OK了。

官方的提示：
      The password file should be read-only and only accessible by the operating system user Tomcat is running as.

 

④ 重新启动Tomcat，在Windows命令行输入“netstat -a”查看配置的端口号是否已打开，如果打开，说明上面的配置成功了。

 

⑤ 使用jconsole测试JMX。

运行$JAVA_HOME/bin目录下的jconsole.exe，打开J2SE监视和管理控制台，然后建立连接，如果是本地的Tomcat则直接选择然后点击连接，如果是远程的，则进入远程选项卡，填写地址、端口号、用户名、口令即可连接。。Mbean属性页中给出了相应的数据，Catalina中是tomcat的，java.lang是jvm的。对于加粗的黑体属性值，需双击一下才可看内容。

 

 

二、使用JMX监控Tomcat示例代码

String jmxURL = "service:jmx:rmi:///jndi/rmi://192.168.10.93:8999/jmxrmi";
JMXServiceURL serviceURL = new JMXServiceURL(jmxURL);

Map map = new HashMap();
// 用户名密码，在jmxremote.password文件中查看
String[] credentials = new String[] { "monitorRole", "tomcat" };
map.put("jmx.remote.credentials", credentials);
JMXConnector connector = JMXConnectorFactory.connect(serviceURL, map);
MBeanServerConnection mbsc = connector.getMBeanServerConnection();

// 端口最好是动态取得
ObjectName threadObjName = new ObjectName("Catalina:type=ThreadPool,name=http-8080");
MBeanInfo mbInfo = mbsc.getMBeanInfo(threadObjName);

// tomcat的线程数对应的属性值
String attrName = "currentThreadCount";
MBeanAttributeInfo[] mbAttributes = mbInfo.getAttributes();
System.out.println("currentThreadCount:" + mbsc.getAttribute(threadObjName, attrName));

 

 

 

 

 

三、完整的示例代码文件

import java.lang.management.MemoryUsage;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Formatter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.management.MBeanAttributeInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanServerConnection;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeDataSupport;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

public class JMXTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {

			String jmxURL = "service:jmx:rmi:///jndi/rmi://127.0.0.1:8999/jmxrmi";

			JMXServiceURL serviceURL = new JMXServiceURL(jmxURL);

			Map map = new HashMap();
			String[] credentials = new String[] { "monitorRole", "tomcat" };
			map.put("jmx.remote.credentials", credentials);
			JMXConnector connector = JMXConnectorFactory.connect(serviceURL,
					map);
			MBeanServerConnection mbsc = connector.getMBeanServerConnection();

			// 端口最好是动态取得
			ObjectName threadObjName = new ObjectName(
					"Catalina:type=ThreadPool,name=http-8080");
			MBeanInfo mbInfo = mbsc.getMBeanInfo(threadObjName);

			String attrName = "currentThreadCount";// tomcat的线程数对应的属性值
			MBeanAttributeInfo[] mbAttributes = mbInfo.getAttributes();
			System.out.println("currentThreadCount:"
					+ mbsc.getAttribute(threadObjName, attrName));

			// heap
			for (int j = 0; j < mbsc.getDomains().length; j++) {
				System.out.println("###########" + mbsc.getDomains()[j]);
			}
			Set MBeanset = mbsc.queryMBeans(null, null);
			System.out.println("MBeanset.size() : " + MBeanset.size());
			Iterator MBeansetIterator = MBeanset.iterator();
			while (MBeansetIterator.hasNext()) {
				ObjectInstance objectInstance = (ObjectInstance) MBeansetIterator
						.next();
				ObjectName objectName = objectInstance.getObjectName();
				String canonicalName = objectName.getCanonicalName();
				System.out.println("canonicalName : " + canonicalName);
				if (canonicalName
						.equals("Catalina:host=localhost,type=Cluster")) {
					// Get details of cluster MBeans
					System.out.println("Cluster MBeans Details:");
					System.out
							.println("=========================================");
					// getMBeansDetails(canonicalName);
					String canonicalKeyPropList = objectName
							.getCanonicalKeyPropertyListString();
				}
			}
			// ------------------------- system ----------------------
			ObjectName runtimeObjName = new ObjectName("java.lang:type=Runtime");
			System.out.println("厂商:"
					+ (String) mbsc.getAttribute(runtimeObjName, "VmVendor"));
			System.out.println("程序:"
					+ (String) mbsc.getAttribute(runtimeObjName, "VmName"));
			System.out.println("版本:"
					+ (String) mbsc.getAttribute(runtimeObjName, "VmVersion"));
			Date starttime = new Date((Long) mbsc.getAttribute(runtimeObjName,
					"StartTime"));
			SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			System.out.println("启动时间:" + df.format(starttime));

			Long timespan = (Long) mbsc.getAttribute(runtimeObjName, "Uptime");
			System.out.println("连续工作时间:" + JMXTest.formatTimeSpan(timespan));
			// ------------------------ JVM -------------------------
			// 堆使用率
			ObjectName heapObjName = new ObjectName("java.lang:type=Memory");
			MemoryUsage heapMemoryUsage = MemoryUsage
					.from((CompositeDataSupport) mbsc.getAttribute(heapObjName,
							"HeapMemoryUsage"));
			long maxMemory = heapMemoryUsage.getMax();// 堆最大
			long commitMemory = heapMemoryUsage.getCommitted();// 堆当前分配
			long usedMemory = heapMemoryUsage.getUsed();
			System.out.println("heap:" + (double) usedMemory * 100
					/ commitMemory + "%");// 堆使用率

			MemoryUsage nonheapMemoryUsage = MemoryUsage
					.from((CompositeDataSupport) mbsc.getAttribute(heapObjName,
							"NonHeapMemoryUsage"));
			long noncommitMemory = nonheapMemoryUsage.getCommitted();
			long nonusedMemory = heapMemoryUsage.getUsed();
			System.out.println("nonheap:" + (double) nonusedMemory * 100
					/ noncommitMemory + "%");

			ObjectName permObjName = new ObjectName(
					"java.lang:type=MemoryPool,name=Perm Gen");
			MemoryUsage permGenUsage = MemoryUsage
					.from((CompositeDataSupport) mbsc.getAttribute(permObjName,
							"Usage"));
			long committed = permGenUsage.getCommitted();// 持久堆大小
			long used = heapMemoryUsage.getUsed();//
			System.out.println("perm gen:" + (double) used * 100 / committed
					+ "%");// 持久堆使用率

			// -------------------- Session ---------------
			ObjectName managerObjName = new ObjectName(
					"Catalina:type=Manager,*");
			Set<ObjectName> s = mbsc.queryNames(managerObjName, null);
			for (ObjectName obj : s) {
				System.out.println("应用名:" + obj.getKeyProperty("path"));
				ObjectName objname = new ObjectName(obj.getCanonicalName());
				System.out.println("最大会话数:"
						+ mbsc.getAttribute(objname, "maxActiveSessions"));
				System.out.println("会话数:"
						+ mbsc.getAttribute(objname, "activeSessions"));
				System.out.println("活动会话数:"
						+ mbsc.getAttribute(objname, "sessionCounter"));
			}

			// ----------------- Thread Pool ----------------
			ObjectName threadpoolObjName = new ObjectName(
					"Catalina:type=ThreadPool,*");
			Set<ObjectName> s2 = mbsc.queryNames(threadpoolObjName, null);
			for (ObjectName obj : s2) {
				System.out.println("端口名:" + obj.getKeyProperty("name"));
				ObjectName objname = new ObjectName(obj.getCanonicalName());
				System.out.println("最大线程数:"
						+ mbsc.getAttribute(objname, "maxThreads"));
				System.out.println("当前线程数:"
						+ mbsc.getAttribute(objname, "currentThreadCount"));
				System.out.println("繁忙线程数:"
						+ mbsc.getAttribute(objname, "currentThreadsBusy"));
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static String formatTimeSpan(long span) {
		long minseconds = span % 1000;

		span = span / 1000;
		long seconds = span % 60;

		span = span / 60;
		long mins = span % 60;

		span = span / 60;
		long hours = span % 24;

		span = span / 24;
		long days = span;
		return (new Formatter()).format("%1$d天 %2$02d:%3$02d:%4$02d.%5$03d",
				days, hours, mins, seconds, minseconds).toString();
	}
}