Jprofiler

stay Java During the development process , We always encounter many exceptions or errors , When the current code size is particularly large, it is impossible to troubleshoot quickly , At this point, we need to use the memory snapshot tool Jprofiler, This article describes in detail Jprofiler Download and related use of tools ！

The total memory allocated by the virtual machine is of the computer memory 1/4, The initialized memory is computer memory 1/64

For example, meet OOM：

1. Expand heap memory

2. Analyze the memory to see if there is a problem , Use memory snapshot analysis tool ,MAT,Jprofiler

MAT,Jprofiler effect ：

1. analysis Dump Memory files , Quickly locate memory leaks

2. Get the data in the heap

3. Get big objects

Jprofiler install ：

Download address ：https://www.ej-technologies.com/download/jprofiler/files

The installed versions of client and server need to be unified , The installation packages are the same , recommend 11.1 edition .

The client machine also needs to be installed JDK, I'm safe JDK8.

Local network is required during installation , If there is no network , He will prompt for a license, You can find an online environment and enter your email address to apply for trial license.

Step one now IDEA Medium Plugins Lower installation Jprofiler：

The second step is to install Jprofiler Software ：

Related configuration keys ：

JProfiler11  Serial number 
L-J11-Everyone#speedzodiac-327a9wrs5dxvz#463a59
A-J11-Everyone#admin-3v7hg353d6idd5#9b4
 

JProfiler10  Serial number 
A-tfbyKUM9Gw-KhGMbpYhS1#14246

S-QCM1I25qH1-CkLfdYOFs2#1018

L-GG5oEVjKQX-xEJjkR3QBb#1847

L-idEVpl1jvU-Ww3AnQGBUY#4148

S-p8q09PhrZp-ioZmzCnXlT#18231

L-Vy82rebM6e-nLYfOEykeP#34152

A-r8m8UInymG-S382j9ujs5#3265

A-iWZjln8l5O-QAG2CyKTeC#26123

L-MTGPt84xpw-06dzulmNLY#301110

L-fuoED44azj-OyQMvOutje#22275

To configure the VM options Enter the following command , You can see dump file ：

-Xms1m -Xmx8m -XX:+HeapDumpOnOutOfMemoryError

At present Java Open file location in file , stay src You can see .hprof file

stay Thread Dump You can see that the main line clearly reports an error in the line ：

Available View JVM Running memory ：

Runtime.getRuntime().maxMemory(); // byte 
Runtime.getRuntime().totleMemory(); 

`java
Runtime.getRuntime().maxMemory(); // byte
Runtime.getRuntime().totleMemory();