每個 Cluster 大概就是 4,000 - 4,500 個 Node JobTracker 是架構瓶頸，Concurrent Task 大概是 40,000 上下 HDFS 只能有一個 Namespace，沒辦法分開管控 /sales、/accounting、... 只能執行 MapReduce Job ... 弱弱的問一下：台灣有多少企業 Cluster 有這麼大？Task 有這麼 多？ 上的應用 (Hive、Pig)，搬到更適合的 Computing Framework (比方說 Tez) 19 / 74 HDFS 也變強了： High Availability 可以有多個 Namespace 可以做 Snapshot I/O 速度快 2.5-5 倍 ... 改造 HDFS -> HDFS2 20 / 74 Hadoop 2.x 架構 比較基本的模組： Hadoop Common

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 16 Modules 205 16.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 16.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 12.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 16 Modules 205 16.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 16.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 12.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 17 Modules 219 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 17 Modules 218 17.1 Namespace management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 17.2 Submodules and statements or through qualified access using the dot-notation, i.e. each module is a so-called namespace as well as a first-class data structure associating names with values. If a top-level expression module, you have to import it or use the name qualified with module names. See the section on namespace management. 13.1 Defining Methods Until now, we have, in our examples, defined only functions