Apache Lens 2.1.0 Beta Incubating 发布
#深圳# 6月10日 亚马逊AWSome Day云计算免费培训报名中Apache Lens 2.1.0 Beta Incubating 发布，这是 Apache Lens 项目的第二次发布，更新信息如下：
bug 修复
[*] Lens Server is not getting shutdown in case if user tries to stop before initialising the server
[*] Explain and prepare not giving correct value for "NumFilters" and "NumHaving"
[*] " not a cube column " error should give correct column name
[*] Registration of predict udf in remote hive server not working
[*] SQLException in database/ldap-backed-database user config loader
[*] Query should fail with invalid time range when from and to are equal
[*] Error Message for missing partition should list all the partitions missing
[*] Session not found error code should be 410
[*] NPE when query fails with execute_timeout api
[*] Explain throwing NPE if table is not present in the cube
[*] NPE when session is gone but the query launched by the session is still getting submitted
[*] Getting syntax error when trying to drop partition from lens-cli when partition doesnt exist
[*] Issue while getting persistent result of finished JDBC query
[*] Exception while purging query : integrity constraint violation, unique constraint or index violation
[*] TestCubeRewriter.testQueryWithNow is failing intermittently
性能改善
[*] Checkstyle/Findbugs violations in code
[*] Add number of possible distinct values for dim-attributes
[*] Add flag to TableReference for user to specify if its a join key reference
[*] Lens-Example should have some facts table in db to run cube query in JDBC
[*] Create symlinks to versioned jars in packaging
[*] Create an example schema and queries from a real world use case
[*] Printing current path while installing the lens-server debian
[*] Add estimate api in driver and REST api in server
[*] Reduce number of metastore lookups during cube query rewriting
[*] Add latency metering for each resolver in cube query rewriter
[*] Add latency metering metrics for all api exposed through REST
[*] Accept db to be set as part of open session call
[*] Add resources to hive driver lazily
新特性：
[*] Add examples execution to ML
[*] Provide a way to add static jars at db level
[*] Add api for adding partitions in batch
详细信息请查看发行页面。
此版本现已提供下载：
http://lens.incubator.apache.org/releases/download.html
Lens 提供了一个统一数据分析接口。通过提供一个跨多个数据存储的单一视图来实现数据分析任务切分，同时优化了执行的环境。无缝的集成 Hadoop 实现类似传统数据仓库的功能。
该项目主要特性：
[*]简单元数据层为数据存储提供抽象视图层
[*]单一的共享模式服务器，基于 Hive 元存储。模式通过数据管道 HCatalog 和分析应用进行共享：
[*]OLAP Cube QL 类似 SQL 的高级语言用来查询和描述存放在不同数据立方体 (Cubes) 中的数据集
[*]JDBC 驱动和 Java 客户端库来处理查询
[*]Lens 应用服务器 - 这是一个 REST 服务器允许用户查询数据，更改数据模型，调度查询和查询的配额限制
[*]基于驱动的架构 允许在报表系统中进行嵌入，例如 Hive、列数据存储、Redshift 等
[*]基于成本算法的引擎选择 - 该算法可优化资源的使用，通过对查询的复杂度自动选择最佳执行引擎
Apache Lens 的架构如下：
页:
[1]