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RSS订阅CMG'08 Award Winning Papers: 提升java APP性能的10大方法
这10条里面最重要的一条:Test, Test, Test!!!!!!!!!!!原因很简单: 你都不知道哪里慢怎么提升性能?原文请从此处下: http://www.cmg.org/conference/cmg2008/awards/...
2009-07-07 15:47:20
543
原创 Lessons from the test lab: investigating a pleasan
This post describes our recent investigation into an interesting performance problem: benchmarks that we were surprised to find running significantly faster than we expected on new hardware. Along the...
2009-04-16 10:34:28
220
原创 Actual Performance, Perceived Performance
Actual Performance, Perceived PerformanceIf you've used Windows Vista, you've probably noticed that Vista's file copy performance is noticeably worse than Windows XP. I know it's one of the first ...
2009-02-05 11:34:56
250
原创 Mathematics for TopCoders
Mathematics for TopCodersBy dimkadimonTopCoder MemberIntroductionI have seen a number of competitors complain that they are unfairly disadvantaged because many TopCoder problems are too ...
2009-01-21 15:25:05
186
字符编码笔记：ASCII，Unicode和UTF-8 （引用）
字符编码笔记：ASCII，Unicode和UTF-8阮一峰 发表于 2007年10月28日 | 分类：首页 -> 档案 -> IT技术 今天中午，我突然想搞清楚Unicode和UTF-8之间的关系，于是就开始在网上查资料。结果，这个问题比我想象的复杂，从午饭后一直看到晚上9点，才算初步搞清楚。下面就是我的笔记，主要用来整理自己的思路。但是，我尽量试图写得...
2009-01-07 10:39:20
128
原创 Performance tuning tips - 43 (have fun)
[img]http://www.fasterj.com/cartoon/cartoon043.PNG[/img]
2008-11-28 14:59:21
132
原创 Performance engineer MUST (4)
必看的一本书Computer Systems: A Programmer's PerspectiveGoogle 一下吧, 这个是"必须的".
2008-11-14 14:41:30
128
原创 Performance engineer MUST (3)
TLBTranslation lookaside bufferhttp://en.wikipedia.org/wiki/Translation_lookaside_buffer
2008-11-14 14:38:50
118
原创 Performance engineer MUST (2)
Spinlock以下来自WikipediaSpinlockFrom Wikipedia, the free encyclopediaJump to: navigation, searchIn software engineering, a spinlock is a lock where the thread simply waits in a loop ("spins...
2008-11-14 11:50:07
113
Performance engineer MUST (1)
As a performance engineer, you must know "Context Switch"If you don't know, I give three suggestions:1> look up it in ur course books2> back to school3> Internet: http://en.wikipedia.org/w...
2008-11-07 15:10:03
141
原创 How to set up a simple LRU cache using LinkedHash
How to set up a simple LRU cache using LinkedHashMapCachesCaches are a simple way to improve the performance of an application that reads data from a "slow" source such as files on disk or ro...
2008-11-03 18:05:37
159
性能优化前请你先做profile
很多developer会忽视，甚至是无视profile的重要性。总是想当然的做些性能优化。经常有developer跑过来说：hey, 给我测测性能，我做了些优化。应该会有提升的。ok, 没问题。我很愿意为你效劳。 但是经常碰到的结果是： 没有或只有很小的提升。你告诉他，他还会认为你什么都不知道，你的测试结果不能说明问题。我想也许是因为developer都认为自己知道的最多，...
2008-10-27 13:49:55
205
原创 关于amazon的存储架构
非常有阅读价值的一篇论文!Dynamo: Amazon’s Highly Available Key-value Store[url]http://www.allthingsdistributed.com/2007/10/amazons_dynamo.html[/url]
2008-10-22 17:20:21
259
原创 ReentrantLock and Synchronized (from peter)
[code="java"]import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock; public class HighContentionSimulator implements Runnable { enum Mode implements Runnab...
2008-10-22 17:05:04
123
木吉他演奏, Eric Clapton 是你的好老师
Clapton不插电(unplugged)里面的歌曲.[img]http://tbn0.google.com/images?q=tbn:iufT0mNXPeAGgM:http://www.guitarnoise.com/blog/wp-content/uploads/2007/11/eric-clapton-unplugged.jpg[/img]推荐里面的三首歌:1> Sign...
2008-10-21 18:07:46
259
关于java锁机制的优化
JVM 级别的锁机制的优化主要针对这两种情况:1> 大多数情况不会存在竞争的锁.2> 被频繁竞争的锁.以下采用事例的方式加以说明. 前三种方法是针对情况1>, 最后一种是针对情况2>.1. lock elision [code="java"] public String getStoogeNames() { Vector v = new Vecto...
2008-10-21 17:14:52
153
关于哲学家就餐问题
你说这一帮哲学家聚到一起吃饭，还一人只有一根筷子，还要吃口饭，放下筷子思考一下。当他们都拿起一根筷子时，发现还少根筷子，谁也不肯放下手中的筷子。结果是都只能饿死了。哎。。。这样不行啊。BTW, 这样吃饭好像很不卫生吧....
2008-10-21 13:45:56
124
ReentrantLock VS Synchronized
Here is a simple benchmark case for testing the performance between ReentrantLock and Synchronized.Machine: 2 phycial processors with hyperthreading enabled (4 logical processors)OS: windows...
2008-10-20 17:57:06
176
Performance test, more than test 性能测试, 不只是测试 (1)
Everytime, when people mention about performance test, some guys would stand out and say: aha, performance test, using loadrunner, collecting performance data, that's it. So, there are many docs talki...
2008-10-16 15:25:29
187
关于性能测试中一些计算方法(throughput, active user...)
我们知道最简单的情况下有如下公式： Throughput = 1 / responseTime (1) 现实情况是用户在提交一个请求后并不会立即发第二个请求，比如用户打开一个页面后，他可能会花些时间来浏览它，我们把这个时间叫思考时间：ThinkTime, 那么公式(1)则进化为： Throughput = 1 / (thinkTime + responseTime) ...
2008-10-08 14:33:54
747
原创 Scalability?
严格上讲，scalability还没有正式定义， 甚至有人觉得这样的词完全是带有商业味的。但我觉得以下的解释很直观：(from Steve Haines) performance measures thespeed with which a single request can be executed, while scalabilitymeasures the ability o...
2008-10-07 14:07:51
453
Something to say (for viewer)
All performance articles are only based on my experience. The purpose that I put them here is trying to collect and shape my thoughts. You may find something lose or wrong. Please leave me some no...
2008-07-01 11:32:47
107
Cray Reminiscences
Kirk Pepperdine's attendence of AMD's performance talk at JavaOne produced a cascade of fascinating memories about Cray optimizations. Here, Kirk relates some of the most interesting optimizations tha...
2007-08-29 15:54:44
146
lock-free
1. http://www.ibm.com/developerworks/java/library/j-jtp11234/--------------------------------------- 2.wait free synchronization
2007-06-18 22:06:44
178
解决java.lang.OutOfMemoryError: PermGen space(转帖)
解决方案就是:在启动服务器时加上指定PermGen区域的内存大小的配置.-XX:PermSize=128m -XX:MaxPermSize=256m 比如:nohup /usr/java/jdk1.5.0_08/bin/java -Dcom.sun.management.jmxremote -Xms512m -Xmx1024m -XX:=128m -XX:MaxPermSize=256m -j...
2007-06-05 18:07:48
112
Performance...
« I used to work for... | Main | Usability for Programmers » Google TechTalk: Open Source Performance TestingGoranka Bjedov - Using Open Source Tools for Performance Testing, Google TechTalk, ...
2007-06-05 15:11:17
118
a nice way to see google video
http://www.isaacmao.com/meta/2006/07/how-to-view-google-video-locally-in.html
2007-06-05 15:10:34
93
数据仓库
数据仓库，英文名称为Data Warehouse，可简写为DW。 数据仓库之父Bill Inmon在1991年出版的“Building the Data Warehouse”一书中所提出的定义被广泛接受——数据仓库（Data Warehouse）是一个面向主题的（Su...
2007-04-18 10:38:51
310
Expressions Transform
Expressions, Conversion and Evaluation with C(All you need to know about Expressions)In this tutorial, I will be writing in detail about an important programming concept i.e. Algebraic Expressions,...
2007-04-13 11:13:26
308
Java cleanup code
Java shutdown hook guarantee that clean-up code is always run, regardless of how the user terminates the application.Here is an example from Hadoop:java 代码 /** * A class to track the ...
2007-04-03 12:20:26
372
Java performance tunning
http://www.javaperformancetuning.com/A quite useful website which contains everything on java performance tunning.
2007-04-03 11:37:16
103
Running IE from command line
Here's a simple way you can run Internet Explorer from the command line:Create a new text file that contains the following line:@start "" /b "C:\Program Files\Internet Explorer\iexplore.exe" %*R...
2007-04-03 10:58:15
93
Unicode and UTF8
What is Unicode?Unicode provides a unique number for every character,no matter what the platform,no matter what the program,no matter what the language.Fundamentally, computers just deal with num...
2007-04-03 10:27:04
89
Daemon Thread Notes
1. 只要程式中的non-Daemon thread都結束了.. 就算有Daemon Thread仍在執行中... 程式一樣會被強制結束... 最簡單的例子就是garbage collector thread.. 2. 如果某個 Thread 是 daemon thread，則它所產生的所有 threads 天生就 具有 daemon 的特性 3. A daemon thread...
2007-04-03 09:16:22
106
How to know the main class of a jar file?
Easy. Here is an implementation from Hadoop.java 代码 /** * A micro-application that prints the main class name out of a jar file. * @author Owen O'Malley */ public cl...
2007-04-02 15:18:39
105
The best chinese BAT tutorial(from www.boofee.net/bigfee/)
如何创建批处理文件？ 不要听了批处理文件就感到很神气，其实这东西很简单的．你用过记事本没有？用过？ 好的．将记事本打开，什么都不用写，然后选择文件，保存．保存类型选择所有文件，文件名则命名为 ＊．bat 这个＊代表是文件名，你可以随便的起．保存好之后，看看你保存的地方，会出现一个白色窗口里有个黄色齿轮的图标．这东西就是你创建的批处理文件，双击他就可以运行，但他现在由于里面没有输入任何命令...
2007-03-27 11:58:41
244
Basics - Binary search
java 代码 public class BinarySearch { public static int search(int element, int[] sortedArray) { int length = sortedArray.length; int left = 0...
2007-03-26 15:53:52
92
MergeSort
MergeSort is a sample solution from the idea Dive - and - Conquer.I show my code below: java 代码 public class MergeSort { public static void sort(int[] arra...
2007-03-23 17:26:16
93
Graph data structure
1. adjacent matrixgood for border scan, bad for space O(n*n), spare matrix mostlyjava 代码 public class GraphMatrix { private int[][] nodeMatrix; private int mat...
2007-03-23 12:04:05
142
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