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layout: page title: “Lens Interpreter for Apache Zeppelin” description: “Apache Lens provides an Unified Analytics interface. Lens aims to cut the Data Analytics silos by providing a single view of data across multiple tiered data stores and optimal execution environment for the analytical query. It seamlessly integrates Hadoop with traditional data warehouses to appear like one.” group: interpreter

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Lens Interpreter for Apache Zeppelin

Overview

Apache Lens provides an Unified Analytics interface. Lens aims to cut the Data Analytics silos by providing a single view of data across multiple tiered data stores and optimal execution environment for the analytical query. It seamlessly integrates Hadoop with traditional data warehouses to appear like one.

Installing and Running Lens

In order to use Lens interpreters, you may install Apache Lens in some simple steps:

1. Download Lens for latest version from the ASF. Or the older release can be found in the Archives.
2. Before running Lens, you have to set HIVE_HOME and HADOOP_HOME. If you want to get more information about this, please refer to here. Lens also provides Pseudo Distributed mode. Lens pseudo-distributed setup is done by using docker. Hive server and hadoop daemons are run as separate processes in lens pseudo-distributed setup.
3. Now, you can start lens server (or stop).

./bin/lens-ctl start # (or stop)

Configuring Lens Interpreter

At the “Interpreters” menu, you can edit Lens interpreter or create new one. Zeppelin provides these properties for Lens.

Interpreter Binding for Zeppelin Notebook

After configuring Lens interpreter, create your own notebook, then you can bind interpreters like below image.

For more interpreter binding information see here.

How to use

You can analyze your data by using OLAP Cube QL which is a high level SQL like language to query and describe data sets organized in data cubes. You may experience OLAP Cube like this Video tutorial. As you can see in this video, they are using Lens Client Shell(./bin/lens-cli.sh). All of these functions also can be used on Zeppelin by using Lens interpreter.

create database newDb

use newDb

create storage your/path/to/lens/client/examples/resources/db-storage.xml

create dimension your/path/to/lens/client/examples/resources/customer.xml

dimension show fields customer

dimension show joinchains customer

create cube your/path/to/lens/client/examples/resources/sales-cube.xml

cube show fields sales

cube show joinchains sales

create dimtable your/path/to/lens/client/examples/resources/customer_table.xml

create fact your/path/to/lens/client/examples/resources/sales-raw-fact.xml

dimtable add single-partition --dimtable_name customer_table --storage_name local 
--path your/path/to/lens/client/examples/resources/customer-local-part.xml

fact add partitions --fact_name sales_raw_fact --storage_name local 
--path your/path/to/lens/client/examples/resources/sales-raw-local-parts.xml

query execute cube select customer_city_name, product_details.description, 
product_details.category, product_details.color, store_sales from sales 
where time_range_in(delivery_time, '2015-04-11-00', '2015-04-13-00')

These are just examples that provided in advance by Lens. If you want to explore whole tutorials of Lens, see the tutorial video.

Lens UI Service

Lens also provides web UI service. Once the server starts up, you can open the service on http://serverhost:19999/index.html and browse. You may also check the structure that you made and use query easily here.