java memory profiling tools

How to remotely monitor and optimize the memory and CPU of Tomcat and Java programs using VISUALVMJVISUALVM is a masterpiece after the Java JConsole, a tool that integrates many tools for analyzing and optimizing Java programs.We can use it to optimize the

=null// execution time consuming memory operation, or call time consuming memory method ... } At this point it is necessary to assign the OBJ value to null to release the reference to the object as soon as possible. Try to cache frequently used objectsAs much as possible to cache objects that are used frequently, you can use arrays, or hashmap containers for caching, but this can cause the system

Poor memory: 48-java Interceptor-Comparison of built-in dynamic proxies and CGLIB in JDK (3), 48-javacglib The dynamic proxy class in Java must implement an interface, and it is said that reflection is not very efficient. Then CGLIB was born.Using CGLib to implement dynamic proxy is not restricted by the interface that the proxy class must implement. Besides, CG

1. Do not use static variables if necessaryDevelopers of Java know that when an object is defined as referenced by the STATAIC variable, the memory that the object occupies will not be recycled. Sometimes, developers define static objects or variables that are often called to improve the performance of the program. Therefore, it is not a common object or variable, not defined as a static type of variable, e

method to have the difference, the individual thinks the instrumentation result will be more accurate, but has not found the relevant information to explain this question. Also use the Jprofiler tool to monitor the details of memory usage. Information:Http://docs.oracle.com/javase/6/docs/api/java/lang/instrument/package-summary.html Instrumentation Introductionhttp://www.javamex.com/tutorials/

memory when the move is removed from it. 2 scope definition is not correct, this is very simple, the method of local variables defined as class variables, class static variables.3 exception without finally{} to release some resources, the JDBC era is also a common thing.4 other reasons I do not understand deeply, such as: swing in the listener without explicit remove; internal classes hold implicit references to external objects; Finalizers cause off

using JDK8 The heap in Java is the largest chunk of memory that the JVM manages, primarily for storing instance objects of various classes. In Java, the heap is divided into two distinct regions: the Cenozoic (young) and the old. The New Generation (young) is divided into three areas: Eden, from Survivor, to Survivor. The purpose of this division is to enable th

from:http://chaosinmotion.com/blog/?p=696Just because it ' s a garbage collected language doesn ' t mean you can ' t leak memory or run out of it. Especially on Android where do I get so little to begin with.Now's course sometimes the answer is so you just need more memory. If your program was a Java command line program to load the entire road map of the the sam

This is a note to read Mat helper. Heap dump is a memory snapshot of the Java process at a specific time. A full GC is usually performed before the heap dump is triggered, so the contents of the dump include the object after the GC.What the dump file contains:1, all objects: class, domain, native value and reference;2, all classes: ClassLoader, class name, super class, Static domain;3,GC Root: A touch-acces

Java memory leaks are mostly due to the fact that objects are left in the global hashmap and cannot be released,If you find a Java applicationProgramThe memory usage shows signs of leakage, So we generally use the following steps for analysis: 1. Dumping the heap dump used by Jav