Parallel Collector Stops Application for Minor/Major GC

This section provides log messages showing that the Parallel Collector stops the application for both Minor GC and Major GC.

The next thing we confirm is stop-the-world behavior of the Parallel Collector. This can be verified with "-XX:+PrintGCApplicationStoppedTime" and "-XX:+PrintGCApplicationConcurrentTime" JVM options:

C:\>\progra~1\java\jdk1.8.0\bin\java -Xms2m -Xmx64m -XX:+UseParallelGC
   -XX:+PrintGCDetails -XX:+PrintGCTimeStamps 
   -XX:+PrintGCApplicationStoppedTime 
   -XX:+PrintGCApplicationConcurrentTime 
   GarbageCollection > output.txt
(Ctrl-C)
   
C:\>type output.txt
Step/TotalMemory/FreeMemory/UsedMemory:

0.735: Application time: 0.1749388 seconds
0.736: [GC (Allocation Failure) [PSYoungGen: 511K->248K(768K)] 1280... 
0.740: [Full GC (Ergonomics) [PSYoungGen: 248K->238K(768K)] [ParOld...
0.755: Total time for which application threads were stopped: 
   0.0197849 seconds, Stopping threads took: 0.0000875 seconds

1   3145728   1821016   1324712                                    

1.760: Application time: 1.0048803 seconds                         
1.760: [GC (Allocation Failure) [PSYoungGen: 748K->248K(768K)] 2189...
1.768: [Full GC (Ergonomics) [PSYoungGen: 248K->0K(768K)] [ParOldGe...
1.786: Total time for which application threads were stopped: 
   0.0255083 seconds, Stopping threads took: 0.0001301 seconds

2   5505024   3124776   2380248                                    

2.776: Application time: 0.9903883 seconds                         
2.776: [GC (Allocation Failure) [PSYoungGen: 474K->224K(768K)] 3156...
2.783: Total time for which application threads were stopped: 
   0.0064196 seconds, Stopping threads took: 0.0001250 seconds

3   5505024   2045928   3459096                                    

3.791: Application time: 1.0084043 seconds                         
3.791: [GC (Allocation Failure) [PSYoungGen: 695K->240K(1024K)] 414...
3.798: Total time for which application threads were stopped: 
   0.0065890 seconds, Stopping threads took: 0.0001242 seconds
...

As we can see from the output:

Conclusion: The Parallel collector does stop the application completely (stop-the-world) for both minor GC and major GC.

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"

 What Is Parallel Collector

 Parallel Collector GC Log Message Format

 "-XX:+PrintGCTaskTimeStamps" - Print GC Threads

 "-XX:ParallelGCThreads=n" - # of Threads

Parallel Collector Stops Application for Minor/Major GC

 PSYoungGen Collector Using Tenuring Age

 Parallel Collector Changing NewRatio and SurvivorRatio

 Parallel Collector Adaptive Size Policy

 Adaptive Size Policy Log Messages

 "-XX:+PrintAdaptiveSizePolicy" - Minor GC Report

 Adaptive Size Policy Changed Survivor Space

 Adaptive Size Policy Changed Eden Space

 Adaptive Size Policy for Best Latency

 Adaptive Size Policy for Best Throughput

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

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

 Object References and Garbage Collection

 Garbage Collection Performance Test Program

 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