Hadoop三种安装模式:单机模式,伪分布式,真正分布式

Hadoop三种安装模式:单机模式,伪分布式,真正分布式 一 单机模式standalone 单机模式是Hadoop的默认模式。当首次解压Hadoop的源码包时,Hadoop无法了解硬件安装环境,便保守地选择了最小配置。在这种默认模式下所有3个XML文件均为空。当配置文件为空时,Hadoop会完全运行在本地。因为不需要与其他节点交互,单机模式就不使用HDFS,也不加载任何Hadoop的守护进程。该模式主要用于开发调试MapReduce程序的应用逻辑。 二 伪分布模式安装 tar xzvf hadoop-0.20.2.tar.gz Hadoop的配置文件: conf/hadoop-env.sh  配置JAVA_HOME core-site.xml  配置HDFS节点名称和地址 hdfs-site.xml  配置HDFS存储目录,复制数量 mapred-site.xml    配置mapreduce的jobtracker地址 配置ssh,生成密匙,使到ssh可以免密码连接 (RSA算法,基于因数不对称加密:公钥加密私钥才能解密,私钥加密公钥才能解密) cd /root ssh -keygen -t rsa cd .ssh cp id_rsa.pub authorized_keys覆盖公钥,就能免密码连接 启动Hadoop bin/start-all.sh 停止Hadoop bin/stop-all.sh 二 完全分布式模式 1. 配置etc/hosts文件,使主机名解析为IP  或者使用DNS服务解析主机名 2. 建立hadoop运行用户: useradd grid>passwd grid 3. 配置ssh密码连入: 每个节点用grid登录,进入主工作目录,ssh -keygen -t rsa生产公钥,然后将每个节点的公钥复制到同一个文件中,再将这个包含所有节点公钥的文件复制到每个节点authorized_keys目录,这个每个节点之间彼此可以免密码连接 4. 下载并解压hadoop安装包 5. …

HADOOP与MPP是什么关系?有什么区别和联系?

适用范围、应用领域分别是什么? 其实MPP架构的关系型数据库与Hadoop的理论基础是极其相似的,都是将运算分布到节点中独立运算后进行结果合并。个人觉得区别仅仅在于前者跑的是SQL,后者底层处理则是MapReduce程序。 但是我们会经常听到对于MPP而言,虽说是宣称也可以横向扩展Scale OUT,但是这种扩展一般是扩到100左右,而Hadoop一般可以扩展1000+,这也是经常被大家拿来区分这两种技术的一个说词。 http://m.thebigdata.cn/show.aspx?articleid=14364    

Delta neutral

In finance, delta neutral describes a portfolio of related financial securities, in which the portfolio value remains unchanged when small changes occur in the value of the underlying security. Such a portfolio typically contains optionsand their corresponding underlying securities such that positive and negative delta components offset, resulting in the portfolio’s value being relatively insensitive …

Dividend future

Reference: https://en.wikipedia.org/wiki/Dividend_future In finance, a dividend future is an exchange-traded derivative contract that allows investors to take positions on future dividend payments. Dividend futures can be on a single company, a basket of companies, or on an Equity index. They settle on the amount of dividend paid by the company, the basket of companies, or …

Standard Deviation

Discrete random variable In the case where X takes random values from a finite data set x1, x2, …, xN, with each value having the same probability, the standard deviation is {\displaystyle \sigma ={\sqrt {{\frac {1}{N}}\left[(x_{1}-\mu )^{2}+(x_{2}-\mu )^{2}+\cdots +(x_{N}-\mu )^{2}\right]}},{\rm {\ \ where\ \ }}\mu ={\frac {1}{N}}(x_{1}+\cdots +x_{N}),} or, using summation notation, {\displaystyle \sigma ={\sqrt …

CME Group

CME Group Inc. (Chicago Mercantile Exchange & Chicago Board of Trade) is an American futures company and one of the largest options and futures exchanges. It owns and operates large derivatives and futures exchanges in Chicago and New York City, as well as online trading platforms. In 2014, it gained regulatory approval to open a …

Moneyness

In finance, moneyness is the relative position of the current price (or future price) of an underlying asset (e.g., a stock) with respect to the strike price of a derivative, most commonly a call option or a put option. Moneyness is firstly a three-fold classification: if the derivative would make money if it were to …

BREAKING DOWN ‘Fundamentals’

By looking at the economics of a business, the balance sheet, the income statement, management and cash flow, investors are looking at a company’s fundamentals, which help determine a company’s health as well as its growth prospects. A company with little debt and a lot of cash is considered to have strong fundamentals. While fundamentals …

What does ‘Fundamentals’ mean

The qualitative and quantitative information that contributes to the economic well-being and the subsequent financial valuation of a company, security or currency. Analysts and investors analyze these fundamentals to develop an estimate as to whether the underlying asset is considered a worthwhile investment. For businesses, information such as revenue, earnings, assets, liabilities and growth are …

Outright Forward

直接远期汇率外汇市场的报价者直接报出远期汇率给询价者。虽然直接远期汇率是经由即期汇率及换汇汇率计算得到的。但直接远期汇率的报价者却不分别标明即期汇率及换汇汇率的部分。

Options, Futures, and Other Derivatives, Eighth Edition

参考书: (1)OPTIONS, FUTURES, AND OTHER DERIVATIVES John C. Hull (Author) (Errata) (2)期权、期货及其他衍生产品 约翰•赫尔 (John C.Hull) (作者), 王勇 (译者), 索吾林 (译者) (3) Book Homepage: http://www-2.rotman.utoronto.ca/~hull/ofod/ (4) PowerPoint Slides: http://www-2.rotman.utoronto.ca/~hull/ofodslides/index.html 导言 (Introduction) 交易所市场 (Exchange-traded markets) 场外市场 (Over-the-counter markets) 远期合约 (Forward contracts) 期货合约 (Futures contracts) 期权合约 (Options) 交易员的种类 (Types of traders) 对冲者 (Hedgers) 投机者 (Speculators) 套利者 (Arbitrageurs) 危害 …

MEASURING HISTORICAL VOLATILITY

The document is in here: http://www.todaysgroep.nl/media/236846/measuring_historic_volatility.pdf The implied volatility of an option is usually compared against historical volatility to see if it is cheap or not. However, while there is only one implied volatility there are many different measures of historical volatility which can use some or all of the open (O), high (H), low …

Options Terminology

tenor:(票据或支票的)期限 For any given asset at any given time, many different option contracts may be trading. Suppose there are four expiration dates and five strike prices for options on a particular stock. If call and put options trade with every expiration date and every strike price, there are a total of 40 different contracts. All …

At The Money

The article is in http://www.call-options.com/at-the-money.html Definition of “At The Money” Option: An option is said to be at the money if the current stock price is equal to the strike price. It doesn’t matter if we are talking about calls or puts. Any call or put whose underlying stock price equals the strike price is …

Black-Scholes-Merton

维纳过程和伊藤引理 (Wiener processes and Ito’s lemma) 马尔科夫性质 (The Markov property) 连续时间随机变量 (Continuous-time stochastic processes) 描述股票价格的过程 (The process for a stock price) 参数 (The parameters) 相关过程 (Correlated processes) 伊藤引理 (Ito’s lemma) 对数正态分布的性质 (The lognormal property) 布莱克-斯科尔斯-默顿模型 (The Black-Scholes-Merton model) 股票价格的对数正态分布性质 (Lognormal property of stock prices) 收益率的分布 (The distribution of the rate of return) 预期收益率 (The expected …