Btrace实战

btrace可以对是针对java平台的一个动态追踪工具。简单点说就是可以在不停服务的情况下，对现网数据进行追踪分析和定位。最近为了定位一个jvm进程退出时java进程的运行情况，我学习了下btrace的使用。

例子：分析指定类中方法的调用和返回情况。
代码：

package com.sun.btrace.samples;

import com.sun.btrace.annotations.*;
import static com.sun.btrace.BTraceUtils.*;

/**
 * A simple example that demonstrates subtype matching by +foo pattern
 * in "clazz" attribute of @OnMethod annotation.
 */
@BTrace
public class YTracer {
	@OnMethod(
			//clazz="com.gameX.sanX.action.base.ServerChannelHandler",
			//clazz="/com\\.gameX.sanX.action.base..*/",
			//clazz="/com\\.gameX\\.sanX\\.action\\..*/",
			//clazz="/com.gameX.gamecore.net..*/",
			// clazz="/com\\.gameX.sanX.service..*/",
			//clazz="/com\\.gameX\\..*/",
			clazz="/com\\.gameX.sanX.service.[a-z].*/",
			method="/.*/",
			location=@Location(Kind.ENTRY)
		 )
		public static void onEntryService(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
			print(strcat(timestamp("yyyy-MM-dd HH:mm:ss.SSS")," - ENTRY "));
			print(pcn);
			print('.');
			println(pmn);
		}

	@OnMethod(
			clazz="/com\\.gameX\\.sanX\\.action\\..*/",
			method="/.*/",
			location=@Location(Kind.ENTRY)
		 )
		public static void onEntryAction(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
			print(strcat(timestamp("yyyy-MM-dd HH:mm:ss.SSS")," - ENTRY "));
			print(pcn);
			print('.');
			println(pmn);
		}

	@OnMethod(
			//clazz="com.gameX.sanX.action.base.ServerChannelHandler",
			//clazz="/com\\.gameX.sanX.action.base..*/",
			//clazz="/com\\.gameX\\.sanX\\.action\\..*/",
			//clazz="/com.gameX.gamecore.net..*/",
			// clazz="/com\\.gameX.sanX.service..*/",
			//clazz="/com\\.gameX\\..*/",
			clazz="/com\\.gameX.sanX.service.[a-z].*/",
			method="/.*/",
			location=@Location(Kind.RETURN)
		 )
		public static void onReturnService(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
			print(strcat(timestamp("yyyy-MM-dd HH:mm:ss.SSS")," - RETURN "));
			print(pcn);
			print('.');
			println(pmn);
		}

	@OnMethod(
			clazz="/com\\.gameX\\.sanX\\.action\\..*/",
			method="/.*/",
			location=@Location(Kind.RETURN)
		 )
		public static void onReturnAction(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
			print(strcat(timestamp("yyyy-MM-dd HH:mm:ss.SSS")," - RETURN "));
			print(pcn);
			print('.');
			println(pmn);
		}
}

运行举例：../bin/btrace 31976 YTracer.java

也可以把监控指令绑定到jvm的启动中

-javaagent:/home/X/btrace-1.2.3/build/btrace-agent.jar=script=./YTracer.class,scriptOutputFile=./mybtrace.log 

不指定监控文件路径的话，默认会在当前进程所在路径下,文件名为btraceScript.class.btrace