Hello Kylin developers, I'm a developer at Apache Lens (incubator.apache.org/projects/lens.html), doc avaialble at http://svn.apache.org/repos/asf/incubator/lens/site/publish/current/index.html, which tries solve similar problem as kylin wrt OLAP cubes. So, i'm sending out this mail to understand commonalties and see if we can reuse and collaborate on some.
Lens is an analytics platform which tries to give the ability to create OLAP cube on top HCatalog tables, supports multiple storages to be the underlying storage for fact and dimension data like HDFS, HBase, traditional DWH, with pluggable execution engines to read the underlying data. Lens provides other services like query lifecycle manager (with history, statistics) which will allow to know which are the frequently queried columns so that aggregated facts can be created on them. You can see OLAP cube in lens here - http://svn.apache.org/repos/asf/incubator/lens/site/publish/current/user/olap-cube.html After going through the kylin docs( http://www.slideshare.net/YangLi43/apache-kylin-deep-dive-2014-dec), i understand (correct me if i'm wrong) that Kylin builds a cube by storing aggregated facts materialized in Hbase, it constructs aggregated facts from tables in HDFS. It also provides ability for administrator to define cube and cubeoids. I see the commonalties are mainly wrt OLAP cube definitions. The differentiators are Kylin gives an execution engine for running a query on cube, whereas Lens doesn't have any execution engine in itself. Let us know if the above details sound fine. If so, can look at what we can do next to understand more. Thanks Amareshwari
