jvm monitor

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

to create new native thread This phenomenon is rare and strange, mainly due to the ratio of jvm to system memory. This is strange because the JVM has been allocated a large amount of memory (such as 1.5 GB) by the system, and it must occupy at least half of the available memory.View JVM memory information use jconsole tool to view

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

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

Solve JVM memory overflow and jvm memory overflow Today I encountered a problem. When I restarted Tomcat 6 when adding the configuration file (*. xml) content, the console reported the error: java. lang. StackOverflowError; That is, stack overflow error. Memory overflow occurs when the memory used by the program is larger than the maximum memory provided by the virtual machine. Memory overflow depends on

Impact of Direct Memory on jvm, jvm memory Direct Memory Direct Memory is an important issue. First, it is neither a part of the running data zone nor a part of the Java Virtual Machine specification. This issue is mainly related to NIO after java1.4, an I/O Method Based on channels and buffers. It can use the Native function library to directly allocate off-heap memory, then, you can use the DirectByteBu

Chapter 5 JVM garbage collector (1): jvm garbage collection (The garbage collection algorithm is a theory, and the garbage collector is a collection algorithm. For details about the collection algorithm, see Chapter 4 JVM garbage collection algorithm.) 1. Seven garbage collectors Serial (Serial GC) ParNew (parallel GC) Parallel Scavenge (Parallel GC collectio

[Switch] Error: no 'server' JVM at 'C: \ Program Files \ Java \ jre6 \ bin \ server \ jvm. dll '. Solution: jre6jvm. dll Problem:Error prompted with java-jar XXX. jar-server-Xms900m-Xmx900m or java-server-versionError: no 'server' JVM at 'C: \ ProgramFiles \ Java \ jre6 \ bin \ server \ jvm. dll '.. SolutionCopy 'serv

Jvm-parent Delegation Model, jvm-parent Delegation Interview Questions Can I write a class called java. lang. System? Answer: Generally, this is not acceptable, but an alternative method can be used to meet this requirement.Explanation: in order not to allow us to write System Classes, class loading adopts a delegation mechanism, which ensures that the class members are given priority and the class members

-xss128k: This JVM parameter is used to configure the stack size to 128kBecause the stack is thread-private (it is unclear to understand the structure of the JVM virtual machine), the exception is generated if we start a thread and call a recursive in the thread./** * VM args:-xss128k * */public class Javavmstacksof {private int stacklength = 1;public void Stackleak () {Stackleng Th++;stackleak ();} publi

) Client VM (build 14.3-b01,mixed mode, sharing)Mixed mode explains and compiles the mixed execution mode by default using this patternjava-xint-versionJava HotSpot (TM) Client VM (build 14.3-b01,interpreted mode, sharing)Interpreted pure Interpretation mode disables JIT compilationjava-xcomp-versionJava HotSpot (TM) Client VM (build 14.3-b01,compiled mode, sharing)Compiled pure compilation mode (fallback to interpreted mode to perform a method that cannot be compiled if the method cannot compil

[JVM] template interpreter-how to generate Assembly codes based on bytecode ?, Jvm Interpreter 1. Background Template interpreter for JVM only: How to generate an assembly code based on the opcode and addressing mode. For the bytecode and sink encoding used in this example, see the previous blog post: pass by value or by reference? 2. Addressing Mode This art

Hi,allThe recent pumping time to organize some of the threads that are generated during the JVM's operation is mainly based on the files generated by our system jstack. Some time ago because of system code problems, resulting in performance bottlenecks, so dump a stack out for analysis. There are a lot of threads in the stack, which requires some experience to troubleshoot, so you have some knowledge of them and can improve the efficiency of troubleshooting. Now the online information is not par

Thread Belongs Description Attach Listener Jvm The Attach listener thread is responsible for receiving external commands and executing the command and returning the result to the sender. Usually we use some commands to ask the JVM to give us some feedback, such as Java-version, Jmap, Jstack, and so on. If the thread is not initialized when the

JVM tuning-New Generation and jvm tuning New Generation A new generation of Java virtual machines, including eden space and two dedicated vor spaces. The new generation is used to store newly created objects. The new generation features fast object updates and produces a large number of "Dead objects" in a short time ". Garbage collection for young generations is called secondary garbage collection (minor