Simple Performance profiling samples by Btrace

If you want to dig into why certain method runs slow than you expected, then you can do performance profiling by Btrace, Here is some simple example i used before, hope this helps, BTW, I used JVisualVM Btrace plugin, it is really easy of use, but Be caution with bugs :)

Calculate method execution time:

 /* BTrace Script Template */
 package com.sun.btrace.samples;  

 import com.sun.btrace.annotations.*;  
 import static com.sun.btrace.BTraceUtils.*;  
 import com.sun.btrace.aggregation.*;  
 @BTrace  
 public class MethodResponseTime {  
      /* put your code here */  
   @TLS  
   private static long starttime;  
   private static Aggregation average = newAggregation(AggregationFunction.AVERAGE);  
   private static Aggregation globalcount = newAggregation(AggregationFunction.COUNT);  
      @OnMethod(  
      clazz = "com.myapp.service.pipeline.PipelineServlet",  
      method = "execute"  
      )  
      public static void onCall(){  
        println("enter this method!");  
     starttime = timeNanos();  
      }  
   @OnMethod(  
      clazz = "com.myapp.operations.PrePopulateResponse",  
      method = "execute",  
   location = @Location(Kind.RETURN)  
      )  
      public static void onReturn(){  
        println("Method End!");  
     int duration = (int)(timeNanos()- starttime)/1000000;  
     println(duration);  
     addToAggregation(average,duration);  
     addToAggregation(globalcount,duration);  
      }  
   @OnTimer(20000)  
   public static void onEvent(){  
     println("----------------");  
     printAggregation("Average", average);  
     printAggregation("Global Count", globalcount);  
     println("----------------");  
   }  
 }  

------------------------------------------------------------

Execution time between code lines:

 /* BTrace Script Template */  
 package com.sun.btrace.samples;  

 import com.sun.btrace.annotations.*;  
 import static com.sun.btrace.BTraceUtils.*;  
 import com.sun.btrace.aggregation.*;  
 @BTrace  
 public class CodeLines {  
 @TLS private static long startTime;  
 @OnMethod(  
 clazz="com.myapp.impl.CommonResourceChangePollingImpl",  
 location=@Location(value=Kind.LINE, line=97)  
 )  
 public static void onEnter(){  
 //println("enter this method");  
 startTime= timeNanos();  
 }  
 @OnMethod(  
 clazz="com.myapp.impl.CommonResourceChangePollingImpl",  
 location=@Location(value=Kind.LINE, line=100)  
 )  
 public static void onReturn(){  
 //println("method end!");  
 int duration = (int)(timeNanos()-startTime)/1000000;  
 println(duration);  
 addToAggregation(average,duration);  
 addToAggregation(globalCount, duration);  
 }  
 @OnTimer(30000)  
 public static void onEvent() {  
 println("---------------------------------------------");  
 printAggregation("Average", average);  
 printAggregation("Global Count", globalCount);  
 println("---------------------------------------------");  
 }  
 }  

PS: it calculates from code line 97 to 100 , but not including 100 execution time itself

--------------------------------------------------------------
Call dump trace:

 /* BTrace Script Template */  
 package com.sun.btrace.samples;  

 import com.sun.btrace.annotations.*;  
 import static com.sun.btrace.BTraceUtils.*;  
 import com.sun.btrace.aggregation.*;  
 @BTrace  
 public class CallTree {  
 @OnMethod(  
 clazz="com.myapp.impl.CommonResourceChangePollingImpl",  
 method="getResourceChanges",  
 location=@Location(value=Kind.LINE, line=-1)  
 )  
 public static void online(@ProbeClassName String pcn, @ProbeMethodName String pmn, int line) {  
 print(strcat(pcn, "."));  
 print(strcat(pmn, ":"));  
 println(line);  
 }  
 }  

-----------------------------------------------------------
Regular expression match on Clazz:

 /* BTrace Script Template */  
 package com.sun.btrace.samples;  

 import com.sun.btrace.annotations.*;  
 import static com.sun.btrace.BTraceUtils.*;  
 import com.sun.btrace.aggregation.*;  
 @BTrace  
 public class RegexMatch {  
 @OnMethod(  
 clazz="/com\\.mycompany\\.service\\..*/",  
 location=@Location(value=Kind.LINE, line=-1)  
 )  
 public static void online(@ProbeClassName String pcn, @ProbeMethodName String pmn, int line) {  
 print(strcat(pcn, "."));  
 print(strcat(pmn, ":"));  
 println(line);  
 }  
 }