SEARCH KEYWORD -- Distributed system


  Different ways to print "Hello world" in Java

This post is not about best practice to print "Hello world" in Java, it is about exploring different capabilities offered by Java. Also there are articles about printing "Hello world" in different programming languages, but this post is not about that. Standard literal The most commonly used way is to use System.out to print"Hello world". System.out.println("Hello world"); Enumeration An enumeration can define a set of values belonging to one category. For example, an enumeration for all months ...

   JAVA,FEATURE     2016-05-21 21:49:48

  Samsung will release 10.1 inch Windows RT Tablet

Today, Samsung not only announced Galaxy Note â…¡, first Windows Phone 8 device Ativ S and camera EK-GC100 Galaxy equipped with Android 4.1 system, but also announced a Windows RT Tablet PC Samsung Ativ Tab.The 10.1-inch Samsung Ativ Tab has a resolution of 1366 x 768,1.5 GHz dual-core processor, 2G RAM, a 32/64G storage space, support for microSD memory expansion. Other configurations as well as the standard Wi-Fi and Bluetooth 4.0, support for USB 2.0, uHDMI and NFC.In addition, the table...

   Samsung,Windows 8,Tablet     2012-08-29 19:36:31

  Be careful when running knife vault command

While using Chef, one would frequently use knife commands which are used to manage resources on the Chef server. One can list all nodes, data bags, vault items and many other stuff on the Chef server. In this post, we would cover one command which may need your attention when using it -- knife vault. On Chef server, one can store data to data bags which can be accessed by registered clients. These data bags usually store the data in plain text format. In some cases, one would need to store data ...

   KNIFE VAULT,KNIFE DATA BAG,CHEF-VAULT,CHEF     2017-08-19 00:26:54

  Want to install 64 bit OS on VirtualBox?

By default, VirtualBox only allows to install 32 bit OS on it. But sometimes, 64 bit OS is wanted for specific uses such as running platform specific tests. To allow installing 64 bit OS on VirtualBox. Below information is needed. Here is the official documentation about 64 bit OS: VirtualBox supports 64-bit guest operating systems, even on 32-bit host operating systems, provided that the following conditions are met: You need a 64-bit processor with hardware virtualization support (see the ...

   VirtualBox,64 bit,hardware virtualization,Ubuntu     2014-11-08 03:52:07

  What does super.clone() do?

Object class has a protected clone() method declared to make it possible for all classes make a clone of itself when needed. The clone() is often used when a new instance of the class is needed while at the same time to maintain the same state as the original object. Any class which wants to have clone enabled has to implement the marker interface Cloneable. If a class which implements Cloneable doesn't override the Object.clone() method, the Object.clone() method will be called to just make a b...

   Cloneable,super.clone(),clone,Java     2015-01-07 05:25:52

  String intern in Java

In Java, == is used to compare whether two objects have the same memory location, equals() is usually used to compare whether two objects have the same time and the same state.  When comparing two strings, normally we just want to know whether they have same content, so we can choose equals(). But since String comparison is so frequently needed, Java has worked on the String class to make == workable when comparing two String literals. The String class maintains a pool of emp...

   JAVA,STRING     2016-04-10 03:35:25

  How does JGSS read Windows native TGT credential?

MS LSA is a protected subsystem that authenticates and logs users onto the local system. The user credential is stored at the native credential cache of LSA on Windows. This kind of credential is often used to authenticate the user to the server, one of the authentication methods is Kerberos. JGSS has provided a native interface which can read the native TGT credential and use it to get the TGS of a service. But how does JGSS read the native TGT credential? Here is a sample code for reading nati...

   KERBEROS,JGSS,MS LSA,NATIVE CREDENTIAL,TGT,SESSION KEY TYPE     2015-03-25 03:42:32

  Statistics on StackExchange

StackExchange is the most popular and professional IT Q&A site, Under StackExchange, there is StackOverflow and other sub sites. Many of us may wonder how this mega site is maintained and what its performance is. A performance page has been released by StackExchange recently. Below is some statistic about this mega site. 560 million page views per month, i.e around 1.9 million PVs per day. For such as big site, it has only 9 web servers and 4 SQL servers(while two of them are in backup mode...

   Stackoverflow,statistic     2015-01-05 02:47:01

  Python FTP Server and Client

Distributed Log File Automated Archive System This week, we will introduce the automated compute cluster nodes' log automated archive system project and FTP Communication utility library module. Program Design Purpose: This project aims to create an FTP server & client lib program for file transfer and a files management system for log data synchronization. We will develop an automated log file archive system that regularly collects newly generated log files from multiple nodes in a compute...

       2024-09-29 04:07:50

  Practice of using spinlock instead of mutex

Spinlock and mutex are two important concepts in multithreading programs. They are used to lock some shared resource to prevent concurrent access which may affect data consistency. But they do have differences, what are the differences? when should we use spinlock instead of mutex? The Theory In theory, when a thread tries to lock a mutex and it does not succeed, because the mutex is already locked, it will go to sleep, immediately allowing another thread to run. It will continue to sleep until...

   Spinlock,Mutex,Concurrency     2014-04-19 21:54:12

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