jvm monitoring

Learn JVM easily (II)-memory model, visibility, Command Re-sorting, jvm Model In the previous article, we introduced the basic running process and memory structure of JVM, and had a preliminary understanding of JVM, in this article, we will explore the visibility of variables in java based on the

Chapter 6 JVM garbage collector (2) jvm garbage collection The previous chapter records several common garbage collectors. For details, see chapter 5 JVM garbage collector (1). 1. G1 Note: From the Perspective, compared with CMS, G1 is different only in the final "filter and recycle" section (CMS is a concurrent cleanup). In fact, the overall heap memory divi

Million threads per JVM and million threads per jvm I. environment requirements:1.64bit Linux2.64bit JDK3. Memory is large enough, 512 GB4. cpu: 64 processorsII. Test Tool: [DieLikeADog. java]Java-server-Xmx6G-Xms6G-Xmn600M-Xss228K-XX: PermSize = 50 M-XX: MaxPermSize = 50 M-XX: + DisableExplicitGC DieLikeADogIII. Check Configuration:1. ps-Lf 2. ulimit-a =>>>> Mainly view the value of-n and-u.3. cat/proc/sys

Memory Allocation for various data types in jvm, and jvm allocation for Data TypesJvm runtime data zone: the memory managed by JVM is divided into the following runtime data zones: Program counters, Java Virtual Machine stacks, local method stacks, Java stacks, and method zones. This article mainly involves: java Virtual Machine station (java stack for short), ja

JVM-1. Compilation, jvm-1 CompilationDirectory 1. compiler Overview 2. compiler Composition 3. Example 4. a deep understanding of the JVM compiler 5. Syntax sugar 6. Supplement 1. compiler Overview 1. The essence of the compiler is the specification is transformed into another specification; it is easy for humans to understand machines. Javac converts the source

[In-depth research on Java] 2. JVM class loading mechanism, in-depth research on jvm 1. First, let's take a look at the Code Execution Process: Ii. significance of research on class loading mechanism It can be seen that class loading is the first step in Java program execution. Studying class loading helps you understand the JVM Execution Process and guides dev

What are the common garbage collectors in Java?In fact, the garbage collector (Gc,garbage Collector) is closely related to the specific JVM implementations, and different vendors (IBM, Oracle), different versions of the JVM, offer different choices. Next, I'll talk about the most mainstream Oracle JDK. Serial GC It is the oldest garbage collector, "Serial" embodied in its collection work is si

Try to talk about static methods and static properties from the point of view of the JVM's memory management principles, please correct me where it is wrong. (joezheng123.javaeye.com/blog/264695)The JVM's memory is divided into two parts: Stack and heap:Stack (stack) is the memory instruction area of the JVM. Stack management is simple, push a certain length byte of data or instruction, stack pointer stack corresponding byte displacement; pop a certai

Jvm learning notes 1 (garbage collection algorithm) and jvm learning notes I. Reasons for the garbage collection mechanism In java, when no object reference points to the memory originally allocated to an object, the memory becomes garbage. A jvm system-level thread Automatically releases the memory block. Garbage collection means that the object no longer needed

Memory, as an important resource in the system, plays a key role in the stable operation and efficient operation of the system, unlike languages like Java and C, which do not require the developer to allocate memory and reclaim memory, but rather the JVM manages the allocation of object memory and the collection of object memory (also known as garbage Collection, GC). This greatly reduces the difficulty of writing the program for developers, but one s

Last written 1. A preliminary understanding of the JVM-the JVM sequence, followed today to write the JVM's operating mechanism.First, the JVM startup processThe Java platform includes the JVM and the Java language, where the JVM is also an application process running in the

JVM garbage collection and jvm garbage collection JVM garbage collection This article attempts to briefly introduce the mainstream JVM garbage collection mechanism. Scope of a garbage collection Discussion JVM memory is divided into several parts: Method Area,

Talking about JVM and memory allocation, talking about JVM Memory Allocation 1. program memory allocation Initial Memory Allocation When a program is ready to run, it first needs memory from the Java virtual machine, but the Java Virtual Machine itself does not have the permission. It can only apply for memory from the operating system. At this time, the Java Virtual Machine will have an initial memory, He

JVM Automatic Memory Management-Java memory area and memory overflow exceptions, jvm-java Abstract: JVM memory division, which may cause memory overflow exceptions. 1. JVMRuntime memory Zone The JVM divides the memory managed by the Java program into the following areas: 1.1Program counters The program counter is a sm

The implementation of bytecode commands in jvm is important, and the implementation of bytecode in jvm is important. Java is interpreted and executed, including the dynamic link feature, which provides a lot of space for flexible expansion during parsing or running. How to compile and parse the inheritance, encapsulation, and polymorphism features of object-oriented languages in

JVM-Garbage Collector, jvm-garbage collection This article mainly introduces several JVM garbage collectors. As shown below, the three above are the new generation collectors, The following three are the collectors of the old generation. The G1 collector can be used for the collection of the new generation and the old generation.

JVM tuning series: garbage collection and jvm Tuning Summary: jvm is a required series, which summarizes some common jvm collection mechanisms for easy reference. Before optimization, we must understand how it runs. java's Garbage Collection is usually called "GC", which was born in The Lisp Language of MIT in 1960,

Chapter 4 JVM garbage collection algorithm and Chapter 4 jvm garbage collection Note: Before reading this article, you need to know how to determine whether the object is alive or not. For details, see Chapter 3 JVM memory recycle area + object survival judgment + reference type + garbage collection thread. Note: This article mainly refers to the distributed Java

Chapter 9 JVM tuning recommendations and chapter 9 JVM tuning recommendations Note: This article mainly references distributed Java applications: basics and practices 1. JVM optimization is mainly about memory optimization, mainly in two aspects: Size of each generation Garbage Collector Selection 2. Size of each generation Common Adjustment Parameters

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