Running Multiple I/O Threads on JRockit

JVM Tutorials - Herong's Tutorial Examples

∟I/O Impact of Multi-Thread Applications

∟Running Multiple I/O Threads on JRockit

This section provides a tutorial example on running multiple I/O intensive threads on JRockit R28.2.7 on a Windows system. Multithreading on I/O intensive operations seems not improving total productivity.

Here are some results of running MultithreadingIoRunner.java with different numbers of threads with the default normal priority:

C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 1
Thread parameter: 1000
Number of threads: 1
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
394 | 441 | 441 | 445
395 | 494 | 494 | 445
396 | 479 | 479 | 445
397 | 482 | 482 | 445
398 | 471 | 471 | 445
399 | 306 | 306 | 445
...


C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 2
Thread parameter: 1000
Number of threads: 2
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
253 | 262 275 | 537 | 551
254 | 288 295 | 584 | 551
255 | 171 381 | 553 | 551
256 |  31 394 | 426 | 551
257 | 131 398 | 529 | 551
258 | 311 317 | 629 | 551
...


C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 4
Thread parameter: 1000
Number of threads: 4
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
601 | 176 189  14 142 | 523 | 631
602 | 227 234  16 214 | 694 | 631
603 | 170 274  37 176 | 658 | 631
604 | 257 252  16 245 | 772 | 631
605 | 124 106 119 117 | 467 | 631
606 | 192 229 109 230 | 762 | 631
...


C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 8
Thread parameter: 1000
Number of threads: 8
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
807 | 100  99 102 49 104 52 95 110 | 714 | 663
808 |  47  40  53 63  42 73 48  67 | 435 | 664
809 |  99  92  98 54  90  1 83 105 | 627 | 665
810 |  55  77  59 80  54 66 66  73 | 533 | 665
811 |  36  35  31 34  28 36 34  37 | 275 | 664
812 |  56  61  59 64  61 50 52  52 | 456 | 664
...


C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 16
Thread parameter: 1000
Number of threads: 16
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
308 | 37 49 51 48 38 51 51 49 54 54 50 52 51 49 54 49 | 791 | 748
309 | 15 39 44 43 46 40 45 38 48 41 46 40 42 52 43 41 | 669 | 748
310 | 13 40 51 49 50 46 53 48 52 48 49 45 50 59 50 48 | 756 | 748
311 | 10 49 42 48 49 49 50 49 51 47 58 48 48 57 50 47 | 757 | 748
312 | 36 34 33 31 32 34 35 33 34 34 38 35 30 40 33 31 | 551 | 748
313 | 49 40 48 42 40 41 39 35 43 40 45 42 38 39 42 43 | 672 | 748
...


C:\>"\Program Files\java\jrockit-jdk1.6.0_45-R28.2.7-4.1.0\bin\java"
   MultithreadingIoRunner 1000 32
Thread parameter: 1000
Number of threads: 32
Monitoring interval: 1
Thread priority: 5
Seconds | Productivity per thread | Total | Average
...
282 | 21 22 22 22 25 19 22 22 21 22 21 21 24 21 21 25 ... | 705 | 638
283 | 12 16 16 16 19 19 16 16 17  8 17 16 19 16 16 18 ... | 544 | 638
284 | 18 18 18 16 21 13 18 16 18 19 18 16 21 19 18 22 ... | 620 | 638
285 | 23 20 22 22 25 18 21 21 23 21 20 19 16 20 21 25 ... | 680 | 638
287 | 18 20 19 19 22 23 19 19 20 18 18 18 22 19 20 23 ... | 627 | 638
287 | 22 21 22 22 23 24 22 21 22 22 21 22 23 21 20 23 ... | 691 | 638
...

The results from JRockit are similar to HotSpot. Multiple threads at the application level does not improve the total productivity at all.

Threads   Productivity   Percent
      1            445   100.00%
      2            551   123.82%
      4            631   141.80%
      8            663   148.99%
     16            748   168.09%
     32            638   143.37%

Last update: 2014.

Table of Contents

About This Book

Downloading and Installing JDK 1.8.0 on Windows

Downloading and Installing JDK 1.7.0 on Windows

java.lang.Runtime Class - The JVM Instance

java.lang.System Class - The Operating System

ClassLoader Class - Class Loaders

Class Class - Class Reflections

Sun's JVM - Java HotSpot VM

JRockit JVM 28.2.7 by Oracle Corporation

JVM Runtime Data Areas