java jprofiler

value and the non-heap maximum value exceeds the physical memory or the maximum operating system limit, the server cannot be started.Tip: Set NewSize and MaxNewSize to be equal. The size of "new" should not be greater than half of "old" because if the old area is not large enough to frequently trigger "Main" GC, greatly reduced performanceJVM uses-XX: PermSize to set the non-heap memory initial value. The default value is 1/64 of the physical memory;Set the maximum non-heap memory size by XX: M

) virtual machine process of the class information, memory, garbage Collection, JIT compilation and other running data, in the absence of a GUI, only provides a plain text console environment on the server, it will be the operating period to locate virtual machine performance issues of the preferred tool.Jstat command formatjstat [option Vmid [interval [s | ms] [COUNT]]This vmid, Vmid and Lvmid are consistent for the local virtual machine process. The parameters interval and count respectively r

Currently, the Java 2 Platform has three versions. These are the Micro version of Java 2 Platform (Java 2 Platform Micro Edition, j2_based) applicable to small devices and smart cards) java 2 Platform Standard Edition (J2SE) for desktop systems and Java 2 Platform Enterprise

Part I: Into Java The first chapter walks into Java Overview Advantages: Rigorous structure, object-oriented programming language; Get rid of the hardware platform constraints, the realization of "write once, run everywhere" ideal; Provides a relatively secure memory management and access mechanism to avoid the most memory leaks and pointer out-of-bounds problems; The Hotspot Code detect

The purpose of this article is to summarize some of my experience in using Java for many years, mainly related to some Java basic knowledge points, so also want to share to just get started Java programmer and intend to enter the Java development of this profession of prospective novice, hope can give you some experien

The purpose of this article is to summarize some of my experience in using Java for many years, mainly related to some Java basic knowledge points, so also want to share to just get started Java programmer and intend to enter the Java development of this profession of prospective novice, hope can give you some experien

Java tutorial-deal with Java's 10 methods in a few weeks, java weeks Java tutorial-10 Java methods in a few weeks Do not confuse Java with JavaScript. The goal of Java is "one compilation and debugging everywhere" (Er, no, it is "

Original source: Csdn DengThe purpose of this article is to summarize some of my experience in using Java for many years, mainly related to some Java basic knowledge points, so also want to share to just get started Java programmer and intend to enter the Java development of this profession of prospective novice, hope

The purpose of this article is to summarize some of my experience in using Java for many years, mainly related to some Java basic knowledge points, so also want to share to just get started Java programmer and intend to enter the Java development of this profession of prospective novice, hope can give you some experien

socket transmission, as long as the talk to support socket communication, through the process of command simple peace talk can communicate. However, the fairness of the client plan is very important. At the same time, it also provides a lot of space for the caller to expand and plan the client to satisfy all kinds of scenarios, bao Luo fault tolerance, website index, obedience, special efficacy needs and embedded framework and so on. Several application points:Cache of gadgets (user's token, pe

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/instru

Link Address: http://my.oschina.net/sunchp/blog/3694121. Background knowledge1). JVM Architecture2). JVM run-time data areaThe JVM memory structure is related to the following reference:http://my.oschina.net/sunchp/blog/3697072. Heap overflow (Outofmemoryerror:java heap space)The heap is where Java holds object instances.Heap overflow can be divided into the following two cases, both of which throw the Outofmemoryerror:java heap space exception:1) Mem

=32M Reserve the amount of memory the code occupies-XX:THREADSTACKSIZE=512 set the thread stack size, using the system default value if 0-xx:+uselargepages using large page memoryIn the daily performance tuning we will basically use the above properties of the blackbody;Debug parameter list:Parameters and their default value descriptions-xx:-citime print consumption at JIT compile time-xx:errorfile=./hs_err_pidWhen there is a problem with the system, you cannot use an external tracking tool (suc

How to Learn Java-Java learning roadmap and java Roadmap How to Learn Java is a problem that many new users often ask me. Now I will briefly describe some things to be learned by the next Java beginner at work: First, we need to understand three aspects of the

Java basic notes-preparations before learning Java, basic notes learning java In the next month, I will share my notes when studying JavaSE with you. I hope my notes will help you. I will post an article every day, which is the essence of my learning of Java. Of course, I will modify every note carefully to make the kn

Java Se=java Standard EditionJava Ee=java Enterprise EditionJava Me=java Mobile EditionSE primarily for desktop applications, console development (JFC)EE Enterprise-level development (JSP,EJB)Me embedded development (mobile, small appliances)Currently, there are 3 versions of the J