GCPerformance.java - Program Output

This section describes output data generated by the GC tuning test program - GCPerformance.java.

Before we do any GC performance tests with the GCPerformance.java, let's run it with no wait time and no warmup to review its output:

C:\>\progra~1\java\jdk1.8.0\bin\javac GCPerformance.java

C:\>\progra~1\java\jdk1.8.0\bin\java GCPerformance 1024 32 32 0 0

Parameters: Size=1024KB, Base=32, Chunk=32, Wait=0ms, Warmup=0
Real:Exec  Lat.     Throughput      Total:Free  Proc.
Time:Time  ms/o  Ave:Min:Max:Chunk   Mem.:Mem.   Obj.
  93:93    2906  344:344:344:344   136776:70251    32
           ----              -----               ----
           |                 |                   |- 32 obj. processed
           |                 |- Throughput: 344 objects per second
           |- Latency: 2906 ms per 1000 objects                           

...           
3918:3918  3448  400:290:695:516   156572:24403  1568
4012:4012  3448  398:290:695:340   156572:89941  1600
...  
38938:38938  3906  399:256:695:410  156572:57171  15552
             ----  ---                          
             |     |                               
             |     |- Ave. throughput: 399 objects per second
             |- Latency: 3906 ms per 1000 objects                           
           
39000:39000  3906  399:256:695:516  156572:24403  15584
...

Descriptions on output columns:

For this running session, the application performance is:

Throughput: 399 objects per seconds 
Latency:    3906 milliseconds per 1000 objects

Last update: 2018.

Table of Contents

 About This Book

 Heap Memory Area and Size Control

 JVM Garbage Collection Logging

 Introduction of Garbage Collectors

 Serial Collector - "+XX:+UseSerialGC"

 Parallel Collector - "+XX:+UseParallelGC"

 Concurrent Mark-Sweep (CMS) Collector - "+XX:+UseConcMarkSweepGC"

 Garbage First (G1) Collector - "+XX:+UseG1GC"

 Object References and Garbage Collection

Garbage Collection Performance Test Program

 GCPerformance.java - GC Performance Test Program

GCPerformance.java - Program Output

 Performance Impact of Wait Time

 Performance Impact of Chunk Size

 Performance Jumps Not Related to GC

 Performance Test and System Interruptions

 "START /REALTIME" - Run JVM with Highest Priority

 GCPerfP99.java - 99th Percentile Performance

 GCPerfP99.java - Output Verification

 Performance Tests on Serial Collector

 Performance Tests on Parallel collector

 Performance Tests on Concurrent collector

 Performance Tests on G1 collector

 Garbage Collection Performance Test Summary

 Outdated Tutorials

 References

 Full Version in PDF/EPUB