The dashDB service (formerly known as the Analytics Warehouse service) available in IBM Bluemix™ provides a powerful, easy-to-use, and agile platform for business intelligence and analytics tasks. It is an enterprise-class managed-service powered by the in-memory optimized, column-organized BLU Acceleration data warehouse technology. With a few clicks of the Bluemix UI, create a ready-to-use business intelligence and analytics service for your application. Then, walk through the steps to create a simple chart-based application that uses the dashDB service and deploy it on Bluemix.
Before you start
To build the application in this article, you need:
- Familiarity with the Ruby programming language
- Familiarity with these Ruby modules:
- Familiarity with using the
cfcloud foundry command line tool
In a step-by-step process, you build and deploy a Ruby-based Sinatra application on Bluemix that uses the dashDB service.
Step 1. Create a basic Sinatra app
- Create a Gemfile for your application that lists the necessary gems
for this application:
source 'https://rubygems.org' gem 'sinatra' gem 'ibm_db' gem 'googlecharts' gem 'rack'
- Install the dependencies:
- Create a simple Sinatra app with method
get '/'to render the index page. Let's name the file bluaccl.rb.
This method is called when a user views the root page.
require 'rubygems' require 'sinatra' require 'ibm_db' require 'json' require 'gchart' Tilt.register Tilt::ERBTemplate, 'html.erb' #Set template engine as erb for Sinatra get '/' do erb :index end
- Under the views folder, create an index.html.erb file with a greeting
message that is rendered by method
<html> <h1>Hello Sinatra</h1> </html>
- Create a rackup file, named config.ru:
require './bluaccl' run Sinatra::Application
- Run your application with the command:
Go to the link http://localhost:9292 and see your Sinatra app.
Step 2. Make queries to the dashDB service
Now you're ready to access the dashDB service from your application by using the ibm_db gem and then run queries against it.
- Access the dashDB service with the ibm_db gem. Retrieve
database credentials from the VCAP_SERVICES environment variable when
your application is running on Bluemix.
#Parse VCAP_SERVICES to get Analytics Warehouse Service credentials if(ENV['VCAP_SERVICES']) # we are running inside PaaS, access database details from VCAP_Services $db = JSON.parse(ENV['VCAP_SERVICES'])["AnalyticsWarehouse"] $credentials = $db.first["credentials"] $host = $credentials["host"] $username = $credentials["username"] $password = $credentials["password"] $database = $credentials["db"] $port = $credentials["port"] else # we are running local, provide local DB credentials $host = "localhost" $username = "bludbuser" $password = "password" $database = "BLUDB" $port = 50000 end
- Connect to the dashDB service, execute queries, and process result sets using the ibm_db gem's APIs.
Step 3. Create a bar graph with Googlecharts
Next, we describe how to draw a bar graph that is based on the data that is retrieved from the dashDB service by using Google Charts. Google Charts provides various options to generate several graph types such as line graphs, bar graphs, or pie charts.
This code example uses the Ruby Googlecharts module, a simple wrapper over the Google Chart API to draw a bar graph for the data we retrieved from the database.
def renderBarGraph data array2011 =  #Array group that contains profits for Brands respectively for year 2011 array2012 =  array2013 =  productNames =  #Render a Bar chart that shows profits of each Product Brand in comparison year-to-year data.each do |product,profitHash| productNames << product profitHash.each do |year, profit| if(year == 2011) array2011 << profit elsif (year == 2012) array2012 << profit else array2013 << profit end if(profit > max) max = profit end end end #Render the Bar chart using the gchart library and return the img html tag for display Gchart.bar( :title => "Profit by Product Brand", :data => [array2011, array2012, array2013], :background => 'efefef', :chart_background => 'CCCCCC', :bar_colors => '0000DD,00AA00,EE00EE', :stacked => false, :size => '600x400', :bar_width_and_spacing => '15,0,30', :legend => ['2011', '2012','2013'], :axis_with_labels => 'x,y', :axis_labels => [productNames.join('|'), [0,(max/2).to_f,max.to_f].join('|')], #:format => 'file', :filename => 'custom_filename.png') #To save to a file :format => 'image_tag',:alt => "Profit by brand img") #To be rendered as an image on web page end
Step 4. Stitch it all together
Now you need to put the code examples in the previous sections together into a functioning application.
First, put the code examples from the previous sections into a file that is
called bluaccl.rb and configure the
'get' methods of the app
to call the
Next, modify the index.html.erb file to provide information about the application and a button that executes the query and displays the charts.
Access the code for these steps in the DevOps Services (JazzHub) repository.
With these steps complete, we are ready to deploy the app on Bluemix.
Step 5. Deploy the app on Bluemix
- Log in to Bluemix. On the Catalog tab of Bluemix, select the Ruby Sinatra run time to create a Ruby Sinatra application:
- Specify the AppName in the Create Application form. For example, bluaccel
- Bind an instance of the dashDB service to the
Click the application in the Dashboard tab of Bluemix and select Add a new service. From the set of Services, select the dashDB service and add it to the application:
- Deploy the app to Bluemix.
Set the cf target and then deploy your application to Bluemix with the db2rubybuildpack. $ cf push bluaccl -b https://github.com/ibmdb/db2rubybuildpack
- Access the route of your app to see the running application.
Click Overview on the left navigation pane of your application:
- To start the app in a new tab or window, click the hyperlink for your application and view the index page:
- Let's see the reports in our application. Click Show profit by Product to see the Profit by Product Brand bar graph chart:
In this example application, you learned how easily you can access the enterprise class dashDB service on Bluemix. With a few clicks, you deployed an application that uses the dashDB features. This quick-and-easy Ruby application responds to web requests and uses the ibm_db and Googlecharts modules to present results that are mined from the data warehouse.
BLUEMIX SERVICE USED IN THIS TUTORIAL:dashDB adds a warehouse database and various analytics tools to your application.