监控应用服务器---使用JMX监控Tomcat

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。

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：
[url]http://tomcat.apache.org/tomcat-6.0-doc/monitoring.html#Enabling_JMX_Remote [/url]


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();  
    }  
}