from: http://stevenbenner.com/2010/07/the-5-types-of-programmers/ps: 评论也很精彩 In my code journeys and programming adventures I’ve encountered many strange foes, and even stranger allies. I’ve identified at least five different kinds of code warriors, s…

1.rdd持久化 2.广播 3.累加器 1.rdd持久化 通过spark-shell,可以快速的验证我们的想法和操作! 启动hdfs集群 spark@SparkSingleNode:/usr/local/hadoop/hadoop-2.6.0$ sbin/start-dfs.sh 启动spark集群 spark@SparkSingleNode:/usr/local/spark/spark-1.5.2-bin-hadoop2.6$ sbin/start-all.sh 启动spark-shell s…

作者简介:aoto 蚂蚁金服·数据体验技术团队 Q:为什么要写这边文章?这篇文章要表达什么? A:我们考虑在SPA应用中使用TS作为开发语言,我们需要一篇系统性介绍TS本身及周边的文章来论证在项目中使用TS作为开发语言是科学合理的,而且是顺势而为的. 导引 TS是什么 为什么要用TS TS能干点什么 使用TS的成本 社区发展 周边生态 深入解读TS 接受TS 权衡 TS是什么 TypeScript = Type + Script(标准JS).我们从TS的官方网站上就能看到定义:TypeScrip…

Shared Variables Spark does provide two limited types of shared variables for two common usage patterns: broadcast variables and accumulators. Broadcast variables allow the programmer to keep a read-only variable cached on each machine rather than sh…

Frequently Asked Questions (FAQ) Origins 起源 What is the purpose of the project? What is the history of the project? What's the origin of the gopher mascot? Why did you create a new language? What are Go's ancestors? What are the guiding principles in…

Spark Programming Guide Link:http://spark.apache.org/docs/2.2.0/rdd-programming-guide.html 每个Spark Application包含一个driver程序(运行main方法)以及在集群中执行不同的并行操作. Spark的一级抽象是RDD(2.0之后推荐使用Dataset)划分在不同节点上的元素的集合支持并行处理和自动的故障恢复. RDD的创建:(1)a file in the Hadoop file sys…

每个job被划分为多个stage.划分stage的一个主要依据是当前计算因子的输入是否是确定的,如果是则将其分在同一个stage,从而避免多个stage之间的消息传递开销. http://spark.apache.org/docs/latest/rdd-programming-guide.html [Spark actions are executed through a set of stages, separated by distributed “shuffle” operations. …

1. Primitive Types        Any data types the compiler directly supports are called primitive types.        Primitive types map directly to types existing in the Framework Class Library (FCL).        For the types that are compliant with the Common La…

1.Programming Language Primitive Types primitive types:Any data types the compiler directly supports. Primitive types map directly to types existing in the Framework Class Library (FCL). use the FCL type names and completely avoid the primitive type…

The conditions used in while and if statements can contain any operators, not just comparisons. The comparison operators in and not in check whether a value occurs (does not occur) in a sequence. The operators is and is not compare whether two object…