VisualVM 远程连接服务器

VisualVM 提供在 Java 虚拟机 (Java Virutal Machine, JVM) 上运行的 Java 应用程序的详细信息。在 VisualVM 的图形用户界面中，您可以方便、快捷地查看多个 Java 应用程序的相关信息。

1.打开 jdk/bin 下的 jvisualvm.exe ，点击 工具->插件，把所有插件下载下来

2.要想监控远程服务器，需要在服务器上运行 jstatd 守护进程。下面以 CentOs 为例

• jstatd 命令介绍
• 在 $JAVA_HOME/bin 下创建安全策略文件，命名为 jstatd.all.policy，内容如下：

grant codebase "file:${java.home}/../lib/tools.jar" {

   permission java.security.AllPermission;

};

• 运行 jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=xxx.xx.xx.xx （hostname 为你的 IP）

如果报错：

> jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=xxx.xx.xx.xx 
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:884)
        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，编辑 $JAVA_HOME/jre/lib/security/java.policy 文件，在最后添加 permission java.security.AllPermission;

[root@izwz99qnmldt4l9edceorzz security]# cat java.policy

// 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 ports
        permission 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;
};

此时，再次运行 jstatd -J-Djava.security.policy=jstatd.all.policy -J-Djava.rmi.server.hostname=xxx.xx.xx.xx，不会再报上面的错误

• 在 Visual VM 上添加远程连接

• 点击确认后，就连接成功

• 下面就可以你的开始监控啦~