java memory profiler

Overview of Java Garbage collection Java GC (Garbage Collection, garbage collection, garbage collector) mechanism, is one of the main differences between Java and C++/C, as Java developers, generally do not need to write memory and garbage cleaning code,

Brief introduction This section is an introduction to the Java Memory Dump diagnostics (MDD4J) troubleshooting tool, which helps you analyze the Java heap to diagnose memory footprint issues. MDD4J's analysis results are provided in the report, which summarizes how the application uses the

Java out-of-heap memory (direct memory unmanaged memory)The benefits of out-of-heap memory are: Can be extended to a larger memory space. For example, more than 1TB or even larger than main

Java obtains information about JVM memory and physical memory. 1 package com. sysinfo; 2 public class MonitorInfo {3/** jvm memory available. */4 private long totalMemory; 5 6/** jvm memory remaining. */7 private long freeMemory; 8 9/** maximum

First, overview:　　　　A Java Virtual machine executes a Java program by dividing the memory it manages into several different data regions that have their own purpose and creation and destruction times, some of which follow the startup of the virtual machine process, and some that depend on the start and end of the user thread to build and destroy.Second, the progr

Java stack memory and heap memoryThe stack memory stores local variables, and the heap memory stores objects. The class where the member variables are located is instantiated and stored in the heap memory. When the local variable method is called, it exists in the stack

Jackson triggered the String. intern () bug, resulting in a continuous increase in memory, JVM-Java Memory leakage, I can use Jackson locally to reproduce this problem. import java.io.IOException; import java.util.Map; import java.util.Random; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml

Reentrantlock in the fair lock and unfair lock as a case analysis, interested students can read the origin and source. It is summarized as follows: When a fair lock and an unfair lock are released, the last one is to write a volatile variable state. Fair lock Fetch Yes, first read the volatile variable. When a non-fair lock is acquired, the volatile variable is first updated with CAs, which has the memory semantics of both volatile r

This article is from the "in-depth understanding of Java Virtual Machine," a book, it is very recommended that you look at this book. Recently began to read this book, intends to open a series of related, to summarize the book's important points of knowledge. Uh, uh, well, that picture request framework is not urgent, because this request framework design content is relatively broad, the current spare time is being prepared, and then will be put up. B

Java improvements-A Brief Introduction to Java memory leaks and a brief introduction to java The most obvious advantage of java is its memory management mechanism. You only need to create an object. java's garbage collection mecha

);I is a local variable, and the reference and value exist in the stack. When the method change execution is complete, I will disappear from the stack.4. BirthDate d1= new BirthDate (7,7,1970);D1 is an object reference, exists in the stack, the object (new BirthDate ()) exists in the heap, where D,m,y is stored in the stack for local variables, and their type is the underlying type, so their data is also stored in the stack. Day,month,year are member variables that are stored in the heap (new Bi

Although in Java we do not care about the release of memory, the garbage collection mechanism helps us to reclaim unwanted objects, but in fact improper operations can also produce memory problems: memory overflow, memory leaksMemory overflow: Out of

Directory Java garbage Collection overview Java Memory Area Java Object Access method Java memory allocation mechanism Java GC Mechanism garbage collector Overview of

This is mainly done in the Java memory area and GC mechanism of knowledge Summary, the following paragraph excerpt from the network, part from the book, the specific links forgotten, because this is the time before the study to do the notes. Also hope that the original people to forgive. 1 Java garbage collection The Java