jvm profiler

How JVM works, how jvm works I. JVM Lifecycle The life cycle of a Java VM is a clear task for executing Java programs. It runs only when the program starts to run, and stops when the program ends. When you run three programs on the same machine, there will be three running Java virtual machines. The Java Virtual Machine always starts with a main () method. This m

JVM exploration-Memory Management (2), jvm exploration Memory Management In the previous article, we introduced the memory structure managed by JVM, that is, the Run-Time Data Areas. Now we will introduce JVM memory allocation and recovery.Static Memory Allocation and dynamic memory allocation

Whether it is YGC or full gc,gc in the process of causing the program to break, the correct choice of different GC policies, tuning the JVM, GC parameters, can greatly reduce the problem caused by the work of the GC, resulting in the operation of the program to improve the efficiency of the Java program. However, the tuning of GC is a very complex process, due to different features of the program, such as: Web and GUI programs have a very big differen

Analysis of JVM garbage collection mechanism and jvm garbage collection First, we need to know that Java's memory allocation and collection are all automatically completed by the JVM garbage collection mechanism. Each JVM implementation may adopt different methods to implement the garbage collection mechanism. Before S

Detailed description of JVM memory partition and garbage collection mechanism, jvm garbage collection When writing Java code, you do not need to worry about whether your New object is released or when. Because the JVM has an automatic garbage collection mechanism. In our previous blog, we talked about the MRC (manual reference counting) and ARC (automatic referen

The JVM defines the range of data that is used during the execution of several programs. Some of the data in this area is created when the JVM is started and destroyed when the JVM exits. The rest of the data is dependent on each thread, created when the thread is created, and destroyed when the thread exits. Program Counter A program counter is a small memory s

Whether it is ygc or full GCProgramDuring running interruption, correctly select different GC policies and adjust JVM and GC parameters, which can greatly reduce the program running interruption caused by GC, in this way, the Java program's work efficiency can be appropriately improved. However, adjusting GC is a very complex process. Because each program has different characteristics, for example, the web and GUI programs are very different (the Web

Although written for many years of Java code, but basically only the JVM when blackbox processing. The book on the JVM has also seen several books, but the results are poor. See OPENJDK code? Not interested. I've had a few weeks of free time, so I decided to write a JVM in the Go language and conquer the JVM monster!Wh

"Great haste makes great waste" JVM startup process The JVM is the environment in which the Java program runs, as well as an application process of an operating system, so it has its own lifecycle and its own code and data space. The JVM works and features mainly refers to the operating system loaded into the JVM,

JVM Memory Model The memory space of the Java Virtual machine (Java MACHINE=JVM) is divided into five parts, respectively:1. Program counter2. Java Virtual machine stack3. Local Method Stack4. Heap5. Method area. The following is an in-depth introduction to these five regions.1. Program Counter 1.1. What is a program counter. A program counter is a small memory space that can be viewed as the line number i

Eclipse modifies jvm parameter optimization methods (2 types) and jvm Optimization This article describes how to modify jvm parameter optimization methods in eclipse (two methods). The details are as follows: When you do not configure eclipse, you will always feel slow to start and use eclipse. In fact, you only need to configure eclipse-related parameters, there

Chapter 7 JVM performance monitoring and troubleshooting tools (1), jvm troubleshooting 1. Locate System Problems Basis GC log Heapdump/hprof File) Thread snapshot (threaddump/javacore file) Running log Exception Stack Tools used for analysis Jps: displays all JVM processes in a specified system. Jstat: Collects

Common debugging Parameters for the JVM:–VERBOSE:GC display information on the output device when a memory collection occurs on a virtual machine-xloggc:filename logging of GC-related log information to a file for analysis-xx:-heapdumponoutofmemoryerror Export the relevant information in this heap when an oom is first encountered-xx:onerror= "-XX:-P rintclasshistogram The column information of the print class instance after Ctrl-break, same as Jmap-hi

Today, I just received an insite letter from csdn, explaining the reason why my previous article was removed from the blog homepage. In fact, I did not care much about the withdrawal of the article, however, I was a little frustrated when I was removed three or four times in a row, so I didn't post any more articles in those days, and I couldn't open the homepage of my blog after I debugged the network environment of my school. I finally got better recently. Suddenly I want to say that I have co

Schematic diagram of the Java Virtual Machine ---- JVM runtime data zone, virtual machine ---- jvm JVM Runtime data zone (JVM Runtime Area)In fact, it refers to the division and allocation of computer memory space during JVM running. This article will discuss the

Memory management and garbage collection are critical points for the JVM, and it is important to understand the basic strategies of memory management and garbage collection for the analysis of Java performance.1. During the process of running the program, a large number of objects are created, most of which are short-period objects, a small part is a long-period object, and for short-period objects, frequent garbage collection is required to ensure th

JVM Memory composition and GC-related content see previous articles: JVM memory composition GC Policy memory request.Example of the meaning of JVM parameters is shown in example analysis Parameter name Meaning Default value -xms Initial Heap Size 1/64 of physical Memory ( The default (minheapfreeratio pa

1) Method Area2) Heap3) Java Stacks4) PC Registers5) Native Method StacksJava's JVM's memory model can be roughly divided into 3 zones:Heap Area:1. All objects are stored, each containing a class-corresponding information. (The purpose of class is to get operation instructions)2.JVM only one heap area (heap) is shared by all threads, and the heap does not hold basic types and object references, only the object itselfStack area:When a thread executes a

This is a creation in Article, where the information may have evolved or changed. Although written for many years of Java code, but basically only the JVM when blackbox processing. The book on the JVM has also seen several books, but the results are poor. See OPENJDK code? Not interested. I've had a few weeks of free time, so I decided to write a JVM in the Go la

This is a creation in Article, where the information may have evolved or changed. Although written for many years of Java code, but basically only the JVM when blackbox processing. The book on the JVM has also seen several books, but the results are poor. See OPENJDK code? Not interested. I've had a few weeks of free time, so I decided to write a JVM in the Go la