Calculator used by Summary Report is inaccurate

[asfimport]

Rubén Laguna (Bug 40791):
Calculator.java used by SummaryReport uses the startTime of the first sample as
start time for it's own calculations. First sample to arrive to summary report
is not always the first sample in time because some operations may have started
earlier and will arrive later because the sample come from a jmeter-server (in
distributed testing with batch mode this is noticiable) or because the time to
complete the sample locally is high.

Furthermore Calculator (and Summary Report) take the endTime of the last sample
to arrive as the endTime for all SummaryReport calculations. This is worse
because in distributed testing the time is not always synchonized to the
millisecond and the samples come in batches.

This produces inaccuracy in the calculations. I'll attach a patch to correct
this behavior. Taking the min of samples startTime and the max of the samples
endTime

Severity: normal
OS: other

[asfimport]

Rubén Laguna (migrated from Bugzilla):
Changes the way SummaryReport calculates the thoughput taking into account the
min and max of startTimes and endTimes. Previous version relies on samples
coming in order to accurately make the calculations. This assumption is false
in distributed testing (very false in batch mode!)

Created attachment calculator.diff: Calculator.java patch to take min and max of startTimes and endTimes into account

calculator.diff

Index: C:/javaopt/eclipse/eclipse_workspaces/jmeter_workspace/JMeter2_2/src/core/org/apache/jmeter/util/Calculator.java
===================================================================
--- C:/javaopt/eclipse/eclipse_workspaces/jmeter_workspace/JMeter2_2/src/core/org/apache/jmeter/util/Calculator.java	(revision 454855)
+++ C:/javaopt/eclipse/eclipse_workspaces/jmeter_workspace/JMeter2_2/src/core/org/apache/jmeter/util/Calculator.java	(working copy)
@@ -105,7 +105,8 @@
         if (startTime == 0){
             startTime=res.getStartTime();
         }
-        elapsedTime=res.getEndTime()-startTime;
+        startTime = Math.min(startTime, res.getStartTime());
+        elapsedTime = Math.max(elapsedTime, res.getEndTime()-startTime);
     }
 
 

[asfimport]

Sebb (migrated from Bugzilla):
Thanks.

The code in SVN branch 2.2 has been fixed, and is in the nightly build:

2-2.20061020