通过windows系统中的VisualVM工具，监控Linux系统的测试环境或uat环境或生成环境，来监控JVM内存。

VisualVm提供在Java虚拟机（Java Virutal Machine，JVM）上运行的java应用程序。

只有按照了jdk，就可以在bin目录下，找到启动程序。

以下是具体步骤：

一、再windows系统中，启动VisualVM

1. 在windows系统中java安装目录中jdk/bin/目录下的jvisualvm.exe启动程序。双击启动。

2. 下载插件

   依次点击：工具-> 插件

二、再Linux系统中，配置远程授权

要监控Linux服务器，需要在该服务器上运行jstatd守护进程。

2.1 配置

jstatd命令也是在jdk/bin/目录下。

执行这个命令之前，需要进行安全策略授权。在jdk/bin目录下，创建名称为jstatd.all.policy的文件，内容如下：

grant codebase "file:${java.home}/../lib/tools.jar" {permission java.security.AllPermission;
};

2.2 启动

配置完后，在jdk/bin目录下执行jstatd命令，命令为：

# jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=ip （hostname 为你的 IP）
# & 是后台运行
./jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=172.16.120.12 &

如果启动报错，错误信息如下：

/usr/local/jdk1.8.0_321/bin/jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=172.16.120.12
Could not create remote object
access denied ("java.util.PropertyPermission" "java.rmi.server.ignoreSubClasses" "write")
java.security.AccessControlException: access denied ("java.util.PropertyPermission" "java.rmi.server.ignoreSubClasses" "write")at java.security.AccessControlContext.checkPermission(AccessControlContext.java:472)at java.security.AccessController.checkPermission(AccessController.java:886)at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)at java.lang.System.setProperty(System.java:792)at sun.tools.jstatd.Jstatd.main(Jstatd.java:139)
​

解决办法：修改/usr/local/jdk1.8.0_321/jre/lib/security/java.policy文件，并在最后增加如下内容：

//添加下面内容
permission java.security.AllPermission;

添加完，整体文件如下：

// Standard extensions get all permissions by default
​
grant codeBase "file:${{java.ext.dirs}}/*" {permission java.security.AllPermission;
};
​
// default permissions granted to all domains
​
grant {// Allows any thread to stop itself using the java.lang.Thread.stop()// method that takes no argument.// Note that this permission is granted by default only to remain// backwards compatible.// It is strongly recommended that you either remove this permission// from this policy file or further restrict it to code sources// that you specify, because Thread.stop() is potentially unsafe.// See the API specification of java.lang.Thread.stop() for more// information.permission java.lang.RuntimePermission "stopThread";
​// allows anyone to listen on dynamic portspermission java.net.SocketPermission "localhost:0", "listen";
​// "standard" properies that can be read by anyone
​permission java.util.PropertyPermission "java.version", "read";permission java.util.PropertyPermission "java.vendor", "read";permission java.util.PropertyPermission "java.vendor.url", "read";permission java.util.PropertyPermission "java.class.version", "read";permission java.util.PropertyPermission "os.name", "read";permission java.util.PropertyPermission "os.version", "read";permission java.util.PropertyPermission "os.arch", "read";permission java.util.PropertyPermission "file.separator", "read";permission java.util.PropertyPermission "path.separator", "read";permission java.util.PropertyPermission "line.separator", "read";
​permission java.util.PropertyPermission "java.specification.version", "read";permission java.util.PropertyPermission "java.specification.vendor", "read";permission java.util.PropertyPermission "java.specification.name", "read";
​permission java.util.PropertyPermission "java.vm.specification.version", "read";permission java.util.PropertyPermission "java.vm.specification.vendor", "read";permission java.util.PropertyPermission "java.vm.specification.name", "read";permission java.util.PropertyPermission "java.vm.version", "read";permission java.util.PropertyPermission "java.vm.vendor", "read";permission java.util.PropertyPermission "java.vm.name", "read";//添加下面内容permission java.security.AllPermission;
};

再次运行jstatd命令就不会报错了，命令如下：

./jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=172.16.120.12 &

三、远程连接

在windows系统中java安装目录中jdk/bin/目录下的jvisualvm.exe启动程序。双击启动。

点击确认，就连接成功了。