com.bigdata.journal

Class AbstractMRMWTestCase.GenerateExperiment

java.lang.Object

com.bigdata.testutil.ExperimentDriver

com.bigdata.journal.AbstractMRMWTestCase.GenerateExperiment

Enclosing class:

AbstractMRMWTestCase

public static class AbstractMRMWTestCase.GenerateExperiment
extends com.bigdata.testutil.ExperimentDriver

Experiment generation utility class.

The follow result summary is for 20 clients with 80% read tasks (9/27/07). The timeout was 30 and the store files grew up to ~160M (for transient).

   bufferMode   readBytes/s writeBytes/s    read    write
   Transient     22,372,313  5,666,728 
   Direct        18,560,143  4,823,312      83%      85%
   Disk          11,315,786  3,001,315      51%      53%
 

The big puzzle here is why Disk is so much slower than Direct. You can see that Direct runs at 83% (reads) or 85% (writes) of Transient while Disk runs at a significantly slow percentage of the Transient performance. This is odd since both methods are writing on the disk! If reads are dragging down performance, then maybe read cache for the DiskOnlyStrategy would be useful? Note that this class uses random selection of addresses to read back so this will defeat any cache once the #of bytes/records written grows large enough.

Version:

$Id$

Author:

Bryan Thompson

Nested Class Summary

Nested classes/interfaces inherited from class com.bigdata.testutil.ExperimentDriver

com.bigdata.testutil.ExperimentDriver.Condition, com.bigdata.testutil.ExperimentDriver.DTDParserHelper, com.bigdata.testutil.ExperimentDriver.Experiment, com.bigdata.testutil.ExperimentDriver.IComparisonTest, com.bigdata.testutil.ExperimentDriver.Result

Field Summary

Fields inherited from class com.bigdata.testutil.ExperimentDriver

INFO, log

Constructor Summary

Constructors

Constructor and Description
AbstractMRMWTestCase.GenerateExperiment()

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(String[] args) Generates an XML file that can be run by ExperimentDriver.

Methods inherited from class com.bigdata.testutil.ExperimentDriver

apply, apply, doMain, getCondition, getInterestingSystemProperties, randomize, replicateConditions, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractMRMWTestCase.GenerateExperiment

public AbstractMRMWTestCase.GenerateExperiment()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Generates an XML file that can be run by ExperimentDriver.

Parameters:

args -

Throws:

Exception