26、Groovy JMX

JMX是defacto标准，用于监控与Java虚拟环境有任何关系的所有应用程序。鉴于Groovy直接位于Java之上，Groovy可以利用已经为Java实现的大量工作。

监视JVM

可以使用java.lang.management中提供的标准类来执行JVM的监视。以下代码示例说明如何完成此操作。

import java.lang.management.*

def os = ManagementFactory.operatingSystemMXBean 
println """OPERATING SYSTEM: 
    OS architecture = $os.arch 
    OS name = $os.name 
    OS version = $os.version 
    OS processors = $os.availableProcessors 
""" 

def rt = ManagementFactory.runtimeMXBean 
println """RUNTIME: 
    Runtime name = $rt.name 
    Runtime spec name = $rt.specName 
    Runtime vendor = $rt.specVendor 
    Runtime spec version = $rt.specVersion 
    Runtime management spec version = $rt.managementSpecVersion 
   """ 

def mem = ManagementFactory.memoryMXBean 
def heapUsage = mem.heapMemoryUsage 
def nonHeapUsage = mem.nonHeapMemoryUsage 

println """MEMORY: 
   HEAP STORAGE: 
        Memory committed = $heapUsage.committed 
        Memory init = $heapUsage.init 
        Memory max = $heapUsage.max 
        Memory used = $heapUsage.used NON-HEAP STORAGE: 
        Non-heap memory committed = $nonHeapUsage.committed 
        Non-heap memory init = $nonHeapUsage.init 
        Non-heap memory max = $nonHeapUsage.max 
        Non-heap memory used = $nonHeapUsage.used 
   """

println "GARBAGE COLLECTION:" 
ManagementFactory.garbageCollectorMXBeans.each { gc ->
   println "    name = $gc.name"
   println "        collection count = $gc.collectionCount"
   println "        collection time = $gc.collectionTime"
   String[] mpoolNames =   gc.memoryPoolNames

   mpoolNames.each { 
      mpoolName -> println "        mpool name = $mpoolName"
   } 
}

当代码执行时，输出将根据运行代码的系统而变化。下面给出了输出的样本。

OPERATING SYSTEM: 
   OS architecture = x86 
   OS name = Windows 7 
   OS version = 6.1 
   OS processors = 4

RUNTIME: 
   Runtime name = 5144@Babuli-PC 
   Runtime spec name = Java Virtual Machine Specification 
   Runtime vendor = Oracle Corporation 
   Runtime spec version = 1.7 
   Runtime management spec version = 1.2

MEMORY: 
   HEAP STORAGE: 
      Memory committed = 16252928 
      Memory init = 16777216 
      Memory max = 259522560 
      Memory used = 7355840

NON-HEAP STORAGE: 
   Non-heap memory committed = 37715968 
   Non-heap memory init = 35815424 
   Non-heap memory max = 123731968 
   Non-heap memory used = 18532232 

GARBAGE COLLECTION: 
   name = Copy 
   collection count = 15 
   collection time = 47 
   mpool name = Eden Space 
   mpool name = Survivor Space

   name = MarkSweepCompact 
      collection count = 0 
      collection time = 0 

      mpool name = Eden Space 
      mpool name = Survivor Space 
      mpool name = Tenured Gen 
      mpool name = Perm Gen 
      mpool name = Perm Gen [shared-ro] 
      mpool name = Perm Gen [shared-rw]

监控Tomcat

为了监视tomcat，在启动tomcat时应设置以下参数 –

set JAVA_OPTS = -Dcom.sun.management.jmxremote 
Dcom.sun.management.jmxremote.port = 9004

-Dcom.sun.management.jmxremote.authenticate=false 
Dcom.sun.management.jmxremote.ssl = false

以下代码使用JMX发现正在运行的Tomcat中的可用MBean，确定哪些是Web模块并提取每个Web模块的处理时间。

import groovy.swing.SwingBuilder

import javax.management.ObjectName 
import javax.management.remote.JMXConnectorFactory as JmxFactory 
import javax.management.remote.JMXServiceURL as JmxUrl 
import javax.swing.WindowConstants as WC 

import org.jfree.chart.ChartFactory 
import org.jfree.data.category.DefaultCategoryDataset as Dataset 
import org.jfree.chart.plot.PlotOrientation as Orientation 

def serverUrl = 'service:jmx:rmi:///jndi/rmi://localhost:9004/jmxrmi' 
def server = JmxFactory.connect(new JmxUrl(serverUrl)).MBeanServerConnection 
def serverInfo = new GroovyMBean(server, 'Catalina:type = Server').serverInfo 
println "Connected to: $serverInfo" 

def query = new ObjectName('Catalina:*') 
String[] allNames = server.queryNames(query, null) 

def modules = allNames.findAll { name -> 
   name.contains('j2eeType=WebModule') 
}.collect{ new GroovyMBean(server, it) }

println "Found ${modules.size()} web modules. Processing ..." 
def dataset = new Dataset() 

modules.each { m ->
   println m.name()
   dataset.addValue m.processingTime, 0, m.path 
}