【正文】
2021032039。2021032039。 Dispatcher則維護 Rule到 Processor的映射,并進行 Rule的匹配工作。采用 JDO ( JPOX)。使用hadoophdfs作為數(shù)據(jù)存儲層;提供類似 SQL的語言( HQL),通過 hadoopmapreduce完成數(shù)據(jù)計算;通過 HQL語言提供使用者部分傳統(tǒng) RDBMS一樣的表格查詢特性和分布式存儲計算特性。 ? Hadoop是一個海量數(shù)據(jù)存儲和計算的分布式系統(tǒng),它由若干個成員組成,主要包括: HDFS、MapReduce、 HBase、 Hive、 Pig 和 ZooKeeper, 其中 HDFS是 Google的 GFS開源版本, HBase 是 Google的 BigTable開源版本, ZooKeeper是 Google的 Chubby開源版本。HDFS有著高容錯性的特點,并且設計用來部署在低廉的( lowcost)硬件上。而且它提供高傳輸率( high throughput)來訪問應用程序的數(shù)據(jù),適合那些有著超大數(shù)據(jù)集( large data set)的應用程序。 ? Hadoop在大量的公司中被使用和研究 Hadoop的體系架構 Hadoop由以下幾個部件組成 : Hadoop Common: The mon utilities that support the other Hadoop subprojects. Avro: A data serialization system that provides dynamic integration with scripting languages. Chukwa: A data collection system for managing large distributed systems. HBase: A scalable, distributed database that supports structured data storage for large tables. HDFS: A distributed file system that provides high throughput access to application data. Hive: A data warehouse infrastructure that provides data summarization and ad hoc querying. MapReduce: A software framework for distributed processing of large data sets on pute clusters. Pig: A highlevel dataflow language and execution framework for parallel putation. ZooKeeper: A highperformance c