hprof Profiling

Giriş

Söz dizimi şöyle

java -agentlib:hprof[=options] ToBeProfiledClass
java -Xrunprof[:options] ToBeProfiledClass
javac -J-agentlib:hprof[=options] ToBeProfiledClass

Options için açıklama şöyle

Option Name and Value  Description                    Default
---------------------  -----------                    -------
heap=dump|sites|all    heap profiling                 all
cpu=samples|times|old  CPU usage                      off
monitor=y|n            monitor contention             n
format=a|b             text(txt) or binary output     a
file=<file>            write data to file             java.hprof[.txt]
net=<host>:<port>      send data over a socket        off
depth=<size>           stack trace depth              4
interval=<ms>          sample interval in ms          10
cutoff=<value>         output cutoff point            0.0001
lineno=y|n             line number in traces?         y
thread=y|n             thread in traces?              n
doe=y|n                dump on exit?                  y
msa=y|n                Solaris micro state accounting n
force=y|n              force output to <file>         y
verbose=y|n            print messages about dumps     y

cpu seçeneği

Örnek - samples

Şöyle yaparız. 

java -agentlib:hprof=cpu=samples,interval=20,depth=20 -jar target.jar

Örnek - samples

Şöyle yaparız. 

java -agentlib:hprof=cpu=samples,interval=20,depth=3 Hello

Açıklaması şöyle

The CPU consumption information is sampled every 20 milliseconds, the stack depth is 3, and the name of the generated profile file is java.hprof.txt, which is in the current directory.

Örnek - times

Şöyle yaparız. 

javac -J-agentlib:hprof=cpu=times Hello.java

Açıklaması şöyle

An example of CPU Usage Times Profiling (cpu=times), which can obtain more fine-grained CPU consumption information than CPU Usage Sampling Profile, and can be detailed to the beginning and end of each method call. Its implementation uses bytecode injection Technology (BCI):

heap seçeneği

Örnek - sites

Şöyle yaparız. 

javac -J-agentlib:hprof=heap=sites Hello.java

Açıklaması şöyle

Example of Heap Allocation Profiling (heap=sites):

Açıklaması şöyle

Although the -Xrunprof:heap=sites parameter can be added to the JVM startup parameters to generate the CPU/Heap Profile file, but it has a great impact on the performance of the JVM, and it is not recommended to use it in an online server environment.

Örnek - dump

Şöyle yaparız. 

javac -J-agentlib:hprof=heap=dump Hello.java

Açıklaması şöyle

An example of Heap Dump(heap=dump), which can generate more detailed Heap Dump information than the above Heap Allocation Profiling: