Java 8 GC Tutorials - Herong's Tutorial Examples - v1.03, by Dr. Herong Yang
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:
herong> \progra~1\java\jdk1.8.0\bin\javac GCPerformance.java herong> \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
Table of Contents
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