diff --git a/hadoop-project/src/site/apt/index.apt.vm b/hadoop-project/src/site/apt/index.apt.vm index 4167f4da720..661d942cece 100644 --- a/hadoop-project/src/site/apt/index.apt.vm +++ b/hadoop-project/src/site/apt/index.apt.vm @@ -18,48 +18,48 @@ Apache Hadoop ${project.version} - Apache Hadoop ${project.version} consists of significant - improvements over the previous stable release (hadoop-1.x). + Apache Hadoop ${project.version} is a minor release in the 2.x.y release + line, building upon the previous stable release 2.4.1. - Here is a short overview of the improvments to both HDFS and MapReduce. + Here is a short overview of the major features and improvements. - * {HDFS Federation} + * {Common} - In order to scale the name service horizontally, federation uses multiple - independent Namenodes/Namespaces. The Namenodes are federated, that is, the - Namenodes are independent and don't require coordination with each other. - The datanodes are used as common storage for blocks by all the Namenodes. - Each datanode registers with all the Namenodes in the cluster. Datanodes - send periodic heartbeats and block reports and handles commands from the - Namenodes. + * Authentication improvements when using an HTTP proxy server. This is + useful when accessing WebHDFS via a proxy server. - More details are available in the - {{{./hadoop-project-dist/hadoop-hdfs/Federation.html}HDFS Federation}} - document. + * A new Hadoop metrics sink that allows writing directly to Graphite. - * {MapReduce NextGen aka YARN aka MRv2} + * {{{./hadoop-project-dist/hadoop-common/filesystem/index.html}Specification work}} + related to the Hadoop Compatible Filesystem (HCFS) effort. - The new architecture introduced in hadoop-0.23, divides the two major - functions of the JobTracker: resource management and job life-cycle management - into separate components. + * {HDFS} - The new ResourceManager manages the global assignment of compute resources to - applications and the per-application ApplicationMaster manages the - application‚ scheduling and coordination. + * Support for POSIX-style filesystem extended attributes. See the + {{{./hadoop-project-dist/hadoop-hdfs/ExtendedAttributes.html}user documentation}} + for more details. - An application is either a single job in the sense of classic MapReduce jobs - or a DAG of such jobs. + * Using the OfflineImageViewer, clients can now browse an fsimage via + the WebHDFS API. - The ResourceManager and per-machine NodeManager daemon, which manages the - user processes on that machine, form the computation fabric. + * 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 per-application ApplicationMaster is, in effect, a framework specific - library and is tasked with negotiating resources from the ResourceManager and - working with the NodeManager(s) to execute and monitor the tasks. + * The SecondaryNameNode, JournalNode, and DataNode web UIs have been + modernized with HTML5 and Javascript. - More details are available in the - {{{./hadoop-yarn/hadoop-yarn-site/YARN.html}YARN}} - document. + * {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. Getting Started