Hadoop1.2.1 Installation--single-node mode and single-machine pseudo-distribution modeFirst, Requirements SectionBefore installing Hadoop on Linux, you need to install two programs first:1) JDK 1.6 (or later). Hadoop is a program written in Java, and Hadoop's compilation and MapReduce operations require the use of JDK. Therefore, you must install JDK 1.6 or later
author Joseph Zimmerman http://www.joezimjs.com Date Created
March 2012
This article is the first of a series of articles that describe the common design patterns used by JavaScript. Design patterns are reliable programming methods that help ensure that your code is easier to maintain, expand, and detach, and that all design patterns are essential when creating large JavaScript applications, especially in large groups. Single case
Single-piece Mode
To some extent, the single-piece mode restricts the creation of classes rather than improving the creation of classes, but it still belongs to the creation mode. The single-piece
The single state design pattern is also called a single case pattern:
1. Single State design mode meaning:
The main function of a single state pattern is to ensure that in object-oriented programming, a class can only have one instance object. As an object's creation patte
1. Meaning of the single-state design model:The main function of the single-state mode is to ensure that only one instance object exists in a class in the object-oriented programming design. As the object creation mode, the singleton mode ensures that a class has only one in
', 'removetest ');Static public function LoadActions (){Return self: :__ __ actions;}Public function runAction ($ action, $ args ){Call_user_func (array ($ this, $ action), $ args );}Protected function addTest ($ name ){Echo ($ name );}}// The following is the test code.APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new
');Static public function LoadActions (){Return self: :__ __ actions;}Public function runAction ($ action, $ args ){Call_user_func (array ($ this, $ action), $ args );}Protected function addTest ($ name ){Echo ($ name );}}// The following is the test code.APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User
mode, which is the core part of the system. I'm sure you can see the code. The Load method is loaded into the App class instance, which is equivalent to some books in the getinstance static method. He's got Addcommand,runcommand. Removecommand three public methods. RunCommand is the core part. It is also the core launcher of the command chain mode. See the source code for the implementation. The code is cl
mode, which is the core part of the system. I'm sure you can see the code. The Load method is loaded into the App class instance, which is equivalent to some books in the getinstance static method. He's got Addcommand,runcommand. Removecommand three public methods. RunCommand is the core part. It is also the core launcher of the command chain mode. See the source code for the implementation. The code is cl
(' addtest ', null);
The App class is designed in a single-piece mode, which is the core part of the system. I'm sure you can see the code. The Load method is loaded into the App class instance, which is equivalent to some books in the getinstance static method. He's got Addcommand,runcommand. Removecommand three public methods. RunCommand is the core part. It is also the core launcher of the comm
(array ($ this, $ action), $ args );}Protected function addTest ($ name ){Echo ($ name );}}// The following is the test code.APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> runCommand ('adduser', 'noa
);APP: Load ()-> addCommand (new Test );APP: Load ()-> runCommand (addTest, null );
The APP class is designed in single-piece mode and is the core part of the system. I believe you can see from the code that the Load method loads APP-class instances, which is equivalent to the getInstance static method in some books. he has three public methods: addCommand, runCommand, and removeCommand. runCommand is the
self: :__ __ actions;}// Run the specified functionPublic function runAction ($ action, $ args ){// If you do not understand the usage of this function, refer to the manual.Call_user_func (array ($ this, $ action), $ args );}// Test the function.Protected function addUser ($ name ){Echo ($ name );}}// Similar User of the Test classClass Test implements IRunAction {Static private $ __actions = array ('addtest', 'modifytest', 'removetest ');Static publ
Function loadactions () {
return self::$__actions;
}
Run the specified function
Public Function Runaction ($action, $args) {
Do not understand this function can be used to refer to the manual
Call_user_func (Array ($this, $action), $args);
}
Just a test function.
protected function AddUser ($name) {
Echo ($name);
}
}
Class Test similar user
Class Test implements irunaction{
static Private $__actions = Array (' Addtest ', ' modifytest ', ' removetest
);APP: Load ()-> addCommand (new User );APP: Load ()-> addCommand (new User );APP: Load ()-> runCommand ('adduser', 'noangels ');APP: Load ()-> addCommand (new Test );APP: Load ()-> runCommand ('addtest', null );
The APP class is designed in single-piece mode and is the core part of the system. I believe you can see f
as the Layoutinflater Service, the first time it loads the class. These services are stored in a hashmap in the form of key-value pairs, where the user simply acquires the corresponding servicefetcher based on key, and then obtains the specific service object through the GetService function of the Servicefetcher object. When first fetched, the Servicefetcher's Creatservice function is called to create the service object, and then the object is cached
; runCommand ('adduser', 'noangels ');APP: Load ()-> addCommand (new Test );APP: Load ()-> runCommand ('addtest', null );
The APP class is designed in single-piece mode and is the core part of the system. I believe you can see from the code that the Load method loads APP-class instances, which is equivalent to the getInstance static method in some books. he has three public methods: addCommand, runCommand,
address of the province, the address of the region server where the-root-table is saved, The address of other region servers and some internal information for zookeeper, as shown in.4) User Table pageYou can access the user table page as shown in the link http://{host name}:60010/table.jsp?name=user provided by the user
BeforeFieldInit StaticSingleton () {}/// ///prevents a default instance of the/// class from being created. /// PrivateSingleton () {}/// ///Gets the instance. /// Public StaticSingleton Instance {Get { return_instance; } } }4.Singleton Mode ExpansionExtend an instance to multiple instances, such as an implementation of an object pool. Transfer calls from the New constructor
(){Return self: :__ __ actions;}// Run the specified functionPublic Function runaction ($ action, $ ARGs ){// If you do not understand the usage of this function, refer to the manual.Call_user_func (Array ($ this, $ action), $ ARGs );}// Test the function.Protected function adduser ($ name ){Echo ($ name );}}// Similar user of the test classClass test implements irunaction {Static private $ __actions = array ('addtest', 'modifytest', 'removetest ');S
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