grcheung的博客

自己在linux学习过程中的vi使用笔记，教你熟练使用vi及vim编辑器。 vi编辑器是所有Unix及Linux系统下标准的编辑器，美国加州大学伯克利分校的Bill Joy所创立[1] ，它的强大不逊色于任何最新的文本编辑器，这里只是简单地介绍一下它的用法和一小部分指令。由于对Unix及Linux系统的任何版本，vi编辑器是完全相同的，因此您可以在其他任何介绍vi的地方进一步了解它。Vi也是Linux中最基本的文本编辑器，学会它后，您将在Linux的世界里畅行无阻。

自己在java学习过程中的笔记，从最基础的创建java环境，java的基础知识，java变量的内存存储过程，到容器，异常，多线程等都有详尽涉及。 Java是一门面向对象编程语言，不仅吸收了C++语言的各种优点，还摒弃了C++里难以理解的多继承、指针等概念，因此Java语言具有功能强大和简单易用两个特征。Java语言作为静态面向对象编程语言的代表，极好地实现了面向对象理论，允许程序员以优雅的思维方式进行复杂的编程

文档是自己对hadoop-2.7进行高可用安装的过程，配置详细。 Apache Hadoop 2.7.3 is a minor release in the 2.x.y release line, building upon the previous stable release 2.7.2. Here is a short overview of the major features and improvements. Common Authentication improvements when using an HTTP proxy server. This is useful when accessing WebHDFS via a proxy server. A new Hadoop metrics sink that allows writing directly to Graphite. Specification work related to the Hadoop Compatible Filesystem (HCFS) effort. HDFS Support for POSIX-style filesystem extended attributes. See the user documentation for more details. Using the OfflineImageViewer, clients can now browse an fsimage via the WebHDFS API. The NFS gateway received a number of supportability improvements and bug fixes. The Hadoop portmapper is no longer required to run the gateway, and the gateway is now able to reject connections from unprivileged ports. The SecondaryNameNode, JournalNode, and DataNode web UIs have been modernized with HTML5 and Javascript. YARN YARN’s REST APIs now support write/modify operations. Users can submit and kill applications through REST APIs. The timeline store in YARN, used for storing generic and application-specific information for applications, supports authentication through Kerberos. The Fair Scheduler supports dynamic hierarchical user queues, user queues are created dynamically at runtime under any specified parent-queue.