Java Tools Tutorials - Herong's Tutorial Notes - Version 5.32, by Dr. Herong Yang
'jstat -gcutil' - Garbage Collection Statistics
This section provides a tutorial example on how to use the 'jstat -gcutil' command to get garbage collection statistics against a specified JVM process ID.
With the garbage collection testing program running, I am ready to test the "jstat" tool. The first test is run "jstat" with the "-gcutil -t" option to get statistic samples on a local JVM process.
1. Run the "jps" to get the process ID of the GarbageCollection.java JVM:
C:\herong>\Progra~1\java\jdk1.8.0\bin\jps -l -m -v 3824 sun.tools.jps.Jps -l -m -v -Dapplication.home=C:\Program Files\java\jdk1.8.0 -Xms8m 3868 GarbageCollection -Xms24m -Xmx24m 2924 PrimeNumberSeeker 10 200 2544 sun.tools.jstatd.Jstatd -p 1234 -Dapplication.home=C:\Program Files\java\jdk1.8.0 -Xms8m -Djava.security.policy=tools.policy
2. Run the "jstat" to get the summary of garbage collection statistics of the GarbageCollection JVM identified by the process ID 3868:
C:\herong>\Progra~1\java\jdk1.8.0\bin\jstat -gcutil -t 3868 1s 30 Time S0 S1 E O P YGC YGCT FGC FGCT GCT 313.7 0.00 99.99 4.20 84.56 0.15 2093 3.653 416 13.998 17.651 314.6 0.00 99.99 0.00 97.66 0.15 2100 3.665 417 14.023 17.688 315.6 0.00 0.00 0.00 71.25 0.15 2106 3.674 419 14.090 17.764 316.7 0.00 99.99 4.20 84.56 0.15 2113 3.687 420 14.124 17.811 317.7 0.00 99.99 0.00 97.66 0.15 2120 3.699 421 14.158 17.858 318.6 0.00 0.00 0.00 71.25 0.15 2126 3.708 423 14.225 17.933 319.7 0.00 99.99 4.20 84.56 0.15 2133 3.721 424 14.259 17.980 320.7 0.00 99.99 0.00 97.66 0.15 2140 3.734 425 14.293 18.027 321.6 0.00 0.00 0.00 71.25 0.15 2146 3.743 427 14.360 18.103 322.7 0.00 99.99 4.20 84.56 0.15 2153 3.756 428 14.394 18.149 323.7 0.00 99.99 0.00 97.66 0.15 2160 3.769 429 14.428 18.196 324.7 0.00 0.00 67.14 71.25 0.15 2166 3.777 431 14.495 18.272 325.7 0.00 99.99 4.20 84.56 0.15 2173 3.790 432 14.528 18.319 326.7 0.00 99.99 0.00 97.66 0.15 2180 3.803 433 14.563 18.366 327.7 0.00 99.99 86.29 97.66 0.15 2185 3.810 434 14.588 18.397 328.7 99.99 0.00 0.00 77.66 0.15 2192 3.821 436 14.656 18.476 329.7 0.00 99.99 71.29 84.56 0.15 2198 3.832 437 14.690 18.522 330.7 0.00 99.99 19.15 97.66 0.15 2205 3.845 438 14.723 18.568 331.7 99.99 0.00 0.00 77.66 0.15 2212 3.855 440 14.791 18.646 332.7 0.00 99.99 71.29 84.56 0.15 2218 3.867 441 14.825 18.692 ...
The last two parameters "1s 30" tells "jstat" to collect 30 samples with an interval of 1 second.
To understand the statistic output, you need to read the full documentation of the "jstat" tool.
Last update: 2015.
Table of Contents
'javac' - The Java Program Compiler
'java' - The Java Program Launcher
'jconsole' - Java Monitoring and Management Console
►'jstat' - JVM Statistics Monitoring Tool
'jps' - JVM Process Status Tool
Listing JVM Processes on the Local Machine with "jps"
'jstatd' - JVM Remote Monitoring Server
Starting 'jstatd' with a Security Policy File
Connecting to 'jps' to Remote 'jstatd'
'jstat' Command Options and Parameters
Garbage Collection Testing Program
►'jstat -gcutil' - Garbage Collection Statistics
Accessing Remote JVM Processes with 'jstat'
jvisualvm (Java VisualVM) - JVM Visual Tool
'javap' - The Java Class File Disassembler
'keytool' - Public Key Certificate Tool