monitor jvm memory

The VisualVM is an all-in-one performance monitoring and failure analysis tool from the JDK, including CPU usage, JVM heap memory consumption, real-time monitoring of threads, class loading, memory dump file analysis, and visual analysis of garbage collection operations, which is helpful for troubleshooting and performance tuning. After installing the JDK in Wind

Transferred from: http://www.javatang.com/archives/2007/12/03/1653250.htmlIf not set, the use of myeclipse often appears as shown in insufficient memory hints.The hint says very clearly: "MyEclipse has detected that less than 5% of the 64MB of Perm Gen (non-heap memory) space remains." This means that only less than 5% of the non-heap memory is currently idle. So

One, the JVM memory model summarizesThere is also a register where the thread runs on top of it1. Program counterRecord the execution location of the thread, the thread private memory, the only area in the Java Virtual Machine specification that does not stipulate any outofmemoryerror conditions2. Thread stacks (VM stack)The default size of the stack is 1M-xss2m

the Agent:java.rmi.server.ExportException:Port alreadyinchUse9008; nested exception is:java.net.BindException:Address alreadyinchUseResolution: in the catalish.sh file, determine whether the start command, if it is start, set the variable, otherwise, do not setjava_opts="$JAVA _opts-xms256m-xmx1024m-xx:permsize=128m-xx:maxpermsize=256m"if[" $"="Start"]; Then Echo "Set Console"; Java_opts="-dcom.sun.management.jmxremote.port=9008-dcom.sun.management.jmxremote.ssl=false- Dcom.sun.management.j

: Cache Hit rate: Cached data is a backup of the data in main memory, if the data required by the instruction is in the cache, we say that the cache hit, and vice versa, need to be obtained from main memory. A good caching strategy should be as high as possible, and how to improve it is a very difficult thing. Cache consistency Problem: We know that the cache is a backup of main

to collect memory). Long-term survival of the object into the old age. The virtual machine defines an age counter for each object, and if the object passes through 1 minor GC then the object will enter the Survivor area, then each time after the minor GC so the object's age plus 1, know to reach the threshold object into the old age area. Determines the age of the object dynamically. If the sum of all objects of the same age in the survivor a

Tags: visual body JVM temp A comparison setting LVM Java_homeUsing VISUALVM to remotely monitor Linux server JVM One, JMX mode: 1. The first thing to do is to modify the configuration file for the JMX service in the JDK to get the appropriate permissions:Enter the/jre/lib/management subdirectory of the root directory where the $java_home resides,A. Copy the Jmxre

Java as an object-oriented, cross-platform language, its object, memory, etc. has been a difficult point of knowledge. And many of the concepts of the name look so similar, many people will be silly to divide the unclear. For example, the JVM memory structure, the Java memory model, and the Java object model we are goi

Address: http://www.iteye.com/topic/802573 There is a wall between Java and C ++ that is surrounded by the dynamic memory allocation and garbage collection technology. The people who look at it want to go in, but the people inside the wall want to come up with it. Overview: For developers engaged in C and C ++ program development, in the memory management field, they are the emperors with the highest power

4 ways to configure stack memory for different scopes of JVM! 1. Set JVM memory in Eclise: Modifies Eclipse's configuration file , works for all projects Modify the Eclipse.ini file under the Eclipse root directory-vmargs// Virtual machine Settings-xms40m// Initial Memory

OverviewThere is a high wall between Java and C + + that is surrounded by dynamic memory allocations and garbage collection techniques, and people outside the walls want to go in, but the people inside the wall want to come out.For developers engaged in C, C + + program development, in the field of memory management, they are the highest power of the emperor is the most basic work of the working people-the

recovery of memory, you may consider using the JVM tuning method to solve, but must go through the physical machine long-term testing, because different parameters may cause different effects. such as-XNOCLASSGC parameters.Two recommended memory detection tools1, Jconsole JDK comes with memory monitoring tool, path JD

Java memory Model and the JVM Memory ManagementOne, theJava memory model:1. main memory and working memory (that is, local memory):　　The main goal of the Java

First, the JVM memory modelThe JVM primarily manages two types of memory: heap and non-heap (permanent zone).1. Heap is a runtime data region where all class instances and arrays of memory are allocated. The heap distinguishes between two chunks, one young Generation and the

the implementation of each hardware platform and operating system is different.　　The JVM needs to implement cross-platform support, which requires a set of its own synchronization protocol to mask the differences between the various underlying hardware and operating systems, thus introducing the Java memory model. For Java developers do not need to care about any hardware details, so there is no concept of

How is the memory area of the JVM divided?In the memory partition of the JVM, some areas are thread-private, some belong to the entire JVM process, some of them throw oom exceptions, others do not, and understanding the memory par

becomes a bottleneck for higher concurrency, we need to monitor and regulate these "automated" technologies.Return the time from 1960 to the present, back to our familiar Java language. In the first chapter of this article, we describe the parts of the Java Memory Runtime area, where the program counter, VM stack, local method stack three regions are born with threads, and the frames in the stack are organ

In the basic concept of Android performance optimization (a)---the four references to Java, speaking of Gcroot, the second memory monitor to detect the leak only said Menmery monitor use, this blog talk about mat to look for memory leaks, In contrast, theMemory Monitor is no

In the previous articles, the system learned the next JVM memory structure, Java memory model, Java object model, but found themselves or the three concepts and differences are more vague, silly points unclear. So there is this article, this article is mainly on these three technical points to make a summary and distinguish, deepen the impression.JVM

Reference: http://oldblog.csdn.net/column/details/16384.html In "Fortress besieged" in a sentence, "people outside the wall want to go in, the wall inside people think out", use this to describe between Java and C + + This memory dynamic allocation and garbage collection technology surrounded by the "wall" is more appropriate. For developers engaged in C, C + +, in the area of memory management, they have a