There's a lot of tools around Big Data. For 2016, there's a few tools for big data that I recommend taking a look at. Visualization, Spark, CDAP and HBase allow you to get the most out of your Hadoop cluster and your existing investment. Adding a few more open source tools to really maximize your big data investment.
D3.js is awesome, but there's libraries to help make it easier to use.NVD3provides a great set of reusable charts like Pie and Bar. I think this library is great for visualization data from Hadoop.
Apache Spark and Big Data
Here is a great article to start with an interesting REST App using HBase. A really nice use case for HBase is Time Series data. Look at HBase with Phoenix for SQL. My favorite named slideshare of the week, DeathStar, which talks about production HBase on YARN. This is cool as it combines a few cool technology and some great tips on CDAP and HBase.
CDAP / Cask Data Application Platform
CDAP puts a nice abstraction layer on top of Hadoop to make it quicker and easier to develop. It's open source collection of projects for Data Collection, exploration, storage, collection and serving. A quick overview of CDAP and some applicationson Hadoop. There is a great documentation set here. It uses HBase, Yarn and Hive, so you get to reuse a lot of your Hadoop knowledge. It adds some cool things on top of Hadoop including Tephra (for Transactions on HBase) and Tigon (real-time streaming with Apache Twill). Here is a cool presentation on streaming analytics.