java memory analyzer

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:1. Each thread contains a stack where only objects of the underlying data type are saved and references to custom objects (not objects), objects are stored in the heap area2. The data in each stack (origi

JVM will throw java if no more memory can be allocated to new objects. lang. outofmemoryerror: Your program will be replaced. Before throwing an OutOfMemoryError, JVM will try to use the Garbage Collector to free up enough space, but this error will be thrown when it finds that there is still not enough space. To solve this problem, you need to know the information of your program objects, such as the obje

Speaking of Java memory leaks, in fact, the definition is not so clear. First, if the JVM has no bugs, there is no "heap space that cannot be recycled" in theory, which means that memory leaks in C/s are not in Java. Second, if the Java program has been holding a reference t

"Could not create the Java Virtual machine" encountered a problem while running Java programs. As follows:The reason is that the Java heap is running out of memory to run the JVM and requires additional memory.Searching for this problem on the Internet is mostly a workaround for a program that modifies the JVM's

, each have pros and cons, in fact, if in the development environment, the use of what kind of tools is irrelevant, as long as the results can be good. However, in the production environment, but can not be arbitrarily selected, because these tools themselves will consume a lot of system resources, if the pressure on a production server, the hasty implementation of these tools, may cause a very unexpected situation. It is best not to monitor the server, remote monitoring will be better, but if y

=heap.bin The meaning of format=b is that the dump comes out of the file in binary format. The meaning of File-heap.bin is that the file name of the dump is heap.bin. (under Linux) perform PS aux first | grep Java, find the JVM's PID, then execute Jmap-dump:format=b,file=heap.bin Analyze Heap The binary heap dump file is parsed into human-readable information, which is naturally required with the help of a professional tool, which is recommended he

and user space is mainly to be considered from the point of view of system stability. Windows 32 operating system default kernel space and user space is 1:1, that is, 2G kernel space, 2G memory space, 32-bit Linux system in the default scale is 1:3, that is, 1G kernel space, 3G memory space.4. Word lengthCPU is one of the main technical indicators, refers to the CPU can be processed in parallel binary bits

Run-time data regionJava Virtual Machine in the process of executing a Java program, it manages the memory divided into a number of different sizes of data fields;These zones have their own uses, as well as creation and destruction times, and some regions exist as virtual machine processes start, and some are built and destroyed depending on the start and end of the user thread. Program counter:The program

Summary Although the Java Virtual Machine (JVM) and its garbage collector (garbage COLLECTOR,GC) are responsible for managing most of the memory tasks, a memory leak may still occur in the Java software program. In fact, this is a common problem in large projects. The first step in avoiding a

]java.lang.outofmemoryerror:java Heap Spacedumping Heap to Java_pid1204.hprof ... Heap dump file created [28024534 bytes in 0.077 secs]exception in thread "main" Java.lang.OutOfMemoryError:Java Heap Spac Eat java.util.Arrays.copyOf (arrays.java:3210) at Java.util.Arrays.copyOf (arrays.java:3181) at Java.util.ArrayList.grow (arraylist.java:261) at java.util.ArrayList.ensureExplicitCapacity (arraylist.java:235) at Java.util.ArrayList.ensureCapacityInternal (arraylist.java:227) at Java.util.ArrayLi

Related articlesJava Concurrent Programming (i) Thread definitions, states, and propertiesJava concurrent Programming (ii) synchronizationJava Concurrency Programming (iii) volatile domainsPrefaceBefore we talked about threading, synchronization, and the volatile keyword, we need to understand Java's memory model for concurrent programming of Java, because the communication between

area is to hold an instance of the object. The Java heap is the primary area of the GC and is sometimes referred to as a "GC heap." The Java heap can also be subdivided: the new Generation and the old: Another detail can be divided into Eden space, from Survivor space, to survivor space and so on. Although it is divided into multiple spaces, it is still the object, which is designed to reclaim

following parameters:-xx:+heapdumponoutofmemoryerror-xx:heapdumppath=./java_pid Generating a memory image file when a memory overflow occurs on the JVM Jhat (JVM Heap Analysis tool): JVM Dump Snapshot Analyzer Tools for offline Analysis of Java heap, he can analyze the heap information files exported from different vi

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