I passed both CCAH & CCDH and here is what I did in that order.

1)www.HadoopExam.com Training Videos and Certification Simulator

Their Videos are very well designed for the core understanding of Hadoop Architecture. The lectures are very precise yet comprehensive, which cuts learning time significantly, besides providing a definite edge in certification exam and job interviews. Trainer did a great job in delivering the essential material in such a concise and effective manner that gives the learner very good foundation in Hadoop framework.

2)http://developer.yahoo.com/hadoop/tutorial/index.html

3)http://hadoop.apache.org/docs/current/

4)Hadoop Definitive Guide_Tom White

5)Hadoop Operations_Eric Sammer

6) Practice : Implemented Simple word count example small program to get hands on.

Thanks

How to Prepare for the Clouderas Hadoop Developer Exam(CCD-410)Big Data,Data ArchitectureJune 8, 2014Comments: 9ClouderasHadoop developer certificationis the most popular certification inthe Big Data and Hadoop community. As Ive recently cleared the CCD-410 exam,I want to take the opportunity to provide fewpoints that helped me with preparing for the exam and moreimportantly learning Hadoop in a practical way.Here arethese:1. Tom WhitesHadoop: The Definitive Guidebook is aninvaluable companionfor you to clear the exam. This may be the only book you need as this will help you to address almost all conceptual questions in the exam. Be sureto grab the 3rdedition (latest till date) that covers YARN.2. Dont overlook the other Apache projects in Hadoops ecosystem like Hive, Pig, Oozie, Flume, and HBase. There will be questions testing your basic understanding of those topics. Refer to the related chapters in the Tom Whites book. Also, there are always very good YouTube videos and tutorials available on the web.3. Understand how to useSqoop. The best way to start may be to create a simple table in MySQL (or any database you choose) and importthe data into HDFS as well as in Hive. Understand the different features of the Sqoop tool. Again, Tom Whites book can be used as well as the Apache Sqoop user guide.4. Understand Hadoop fs shellcommandsto manipulate the files in HDFS.5. To clear the exam you need to be hands-on in the basics of MapReduce programming, period. You will find a lot ofquestions in the CCD-410 exam askingabout the outcome/possible result set based on a given MapReduce code snippet. Youneed to know and practice is how to convert the common SQL data access patterns into MapReduce paradigm.Also, there will be questions to test your familiarity on key classes used in the driver class and the methods used (for example: Job class and how it is used to submit a Hadoop job)Tip: Create two simple text files with few recordssimilar to standard emp and dept tables. Load the files into HDFS. Then developand test your MapReduce programs to produce outputs similar to thefollowing queries: Select empl_no, empl_name from emp; Select distinct dept_name from dept; Select empl_no, empl_name from emp where salary > 75000; Select empl_name, dept_no, salary from emp order by dept asc, salary desc Select dept_no,count(*) from emp group by dept_name having count(*) > 1 order by dept_name desc; Select e.empl_name, d.dept_name from emp e join dept d on e.dept_no = d.dept_no;6. You are expected to understand basicJava programming concepts. This is no sweat for the persons regularly working in the Java environment, but for the rest of us a basic Java refresher course will be very handy. Pay particular attention to the following topics that will be very helpful in writing and understandingMapReduce codes. Regular Expression String handling in Java Arrays processing Collection Framework7. Finally, dont forget to refer to theClouderawebsite for the latest updates, study guides and sample questions for thespecific certification you are targeting.Note that you can optionally buy a practice test from Cloudera website. If you have a good preparation andwant to self-check your exam readiness you may try this out (Disclaimer: I did it).I also recommend that you to go through the following article from Mark GschwindsBI Blog. The articlegives you a solid direction to jumpstart your preparation as well aslearning Hadoop.All the best in your journey to learn Hadoop and get certified! Pleaseshare your experience and comments.