java heap dump

= Connector.getmbeanserverconnection (); ObjectName ObjectName =NewObjectName ("Java.nio:type=bufferpool,name=direct") ; Mbeaninfo mbinfo = Mbsc.getmbeaninfo (objectName); for(Mbeanattributeinfo i:mbinfo.getattributes ()) {System.out. println (I.getname () +":"+ Mbsc.getattribute (ObjectName, I.getname ()));}Second, using unsafe reflection calls directly requested out of the heap memoryJava is not available, requires tools like Gperftools to view, ne

Usually we define a variable of the basic data type, a reference to an object, and a live save for a function call uses the stack space in memory, while objects created by the new keyword and constructor are placed in the heap space; the literal amount of the program (literal) is 100, "Hello", which is written directly. And constants are placed in a static storage area. Stack space operation is the fastest but also very small, usually a large number o

http://heylinux.com/archives/1085.html using thread dump analysis to find Java code with high CPU consumption and memory overflowFirst of all, I want to thank my good friend Zhao to share the experience of the flower.I believe that in the actual work, you will certainly encounter high CPU consumption and memory overflow caused by the code.Usually when this happens, we take it for granted that the developer

JstackTo print out the Java stack information for a given Java process ID or core file or remote Debugging service, if it is on a 64-bit machine, the option "-J-D64" needs to be specified, and the Jstack usage of Windows supports only the following:Jstack [-l][f] PIDIf a Java program crashes generating a core file, the Jstack tool can be used to obtain informatio

Heap sorting tool class (applicable to top k problems, java generic implementation) and heap sorting tool class The Code is as follows: 1 public class HeapSort {2 // method function: retrieve the minimum k values in the list. 3 public static

#背景提要It's been a long time since you deployed the code yourself, and the command line's intimacy is getting lower. Released the keyboard, accustomed to the mouse operation of the Windows environment. Sudden practical deployment is also good.Often at the time of deployment, OPS students are blind to [hs_err_pid] files. As everyone knows, this is the Java Virtual machine crash log.#这次是如何分析问题的? First, viewLog Header file## A fatal error has been detected

I encountered a problem yesterday. I changed a common project to a web project. I have already discussed how to modify it. Here I will focus on how to handle the java. lang. outofmemoryerror: Java heap space exception I learned from the online query that this is Java. Lang. outofmemoryerror:

the JVM. When we create objects, they are stored in the Java heap memory. To facilitate garbage collection, the Java heap space is divided into three zones, called New Generation, old Generation or tenured Generation, and perm space. You can resize the Java

thread, its thread is responsible for executing a self-polling loop function ( Refer to: VMThread.cpp void Vmthread::loop ()), the loop function takes precedence from the Vmoperationqueue queue to take out the Action object (vm_operation) that is currently required, and calls the VM The _operation->evaluate function executes the business logic of the operation type itself.The PS:VM operation type is defined in the Vm_operations.hpp file and is listed in several ways: Threadstop, Threaddump, Pri

The 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 to the ceiling, so dump a stack out for analysis. See stack actually also need certain experience, after all, it inside many threads can't all have problem, so, need to have certain understanding to them. Now there are f

The 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 to the ceiling, so dump a stack out for analysis. See stack actually also need certain experience, after all, it inside many threads can't all have problem, so, need to have certain understanding to them. Now there are f

How to make Ambari the hive Service in Output Java Dump file1, select "Hive"2, click on the "Configs" tab3, scroll the screen, select "Advanced Hive-env", in the Hive-env template field note the original "Export hadoop_client_opts="-xmx${hadoop_heapsize}m $HADOOP _ Client_opts "Modify the following:#export hadoop_client_opts= "-xmx${hadoop_heapsize}m $HADOOP _client_opts"Export hadoop_client_opts= "-xmx${ha

Error background: Since the file is stored on a third-party server, all need to be told to convert the received Multipartfile file to files and then transfer. (Spring MVC)The following two methods have been found through search engines.are declared in the preceding spring XML. As follows:id= "Multipartresolver" class= " Org.springframework.web.multipart.commons.CommonsMultipartResolver "/> If you want to add the largest, minimum range control, please Baidu reference.Method One: Strong turnMeth

crucial, and "best guess" is made about the Java heap settings ", simulate the application behavior and perform appropriate analysis, load, and performance tests to verify the Java heap memory requirements. We recommend the Jprofiler tool to you. The best way to learn how to use a analyzer is to correctly understand t

Java calls Mysql dump to back up the database SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMddHHmmss "); Try {String name = sdf. format (new Date ());String filePath = System. getProperty ("user. dir") + "//" + name + ". SQL ";// System actuatorRuntime rt = Runtime. getRuntime ();// Export Database statementsStringBuffer cmd = new StringBuffer ();Cmd. append ("mysqldump-u ");Cmd. append (ServeConfig.

concurrent collector is used for collecting data in parallel in the young generation. Number of parallel collection threads.Others-XX: PermSize = 10 m and-XX: MaxPermSize = 10 m limit the size of the method area.-XX: MaxDirectMemorySize = 10 m specifies the DirectMemory (Direct Memory) capacity. If not specified, the default value is the same as the maximum value of the JAVA heap (-Xmx.-XX: + HeapDumpOnOut