Writing by shivdev on Thursday, 25 of September , 2014 at 2:37 pm
When I was starting pig using pig -x local
, I was getting the following error.
Exception in thread “main” java.io.IOException: Permission denied
at java.io.UnixFileSystem.createFileExclusively(Native Method)
at java.io.File.createNewFile(File.java:1006)
at java.io.File.createTempFile(File.java:1989)
at org.apache.hadoop.util.RunJar.main(RunJar.java:119)
Luckily after some searching stackoverflow had the the solution which was that ${hadoop.tmp.dir} didn’t have permissions.
I was trying to run pig as a different user, than the hadoop user.
sudo chown -R user:group /app/hadoop/tmp
Category: Hadoop,Pig
Writing by shivdev on Tuesday, 5 of August , 2014 at 4:53 am
So today I passed the Cloudera Certified Developer for Apache Hadoop (CCDH) Exam in my first attempt! YAY! If you’re curious, here’s my certificate and here’s the verification link.
For sure, it is NOT a trivial exam to pass without studying and requires at least a few weeks of preparation/practice.
Recommended Study Material in the order that worked for me:
- Mock/Practice Tests : You will know what types of problems to expect
- Hadoop Videos on YouTube! : Gives you a head start if you’re new or need a refresher
- Hadoop In Action by Chuck Lam : Very interesting/stimulating read, though its based on the old API
- Hadoop : The Definitive Guide by Tom White : Comprehensive and gives you an understanding of Hadoop in theory (not a fast read)
- Hadoop in Practice by Alex Holmes : A little more advanced (I didn’t have time to read more than the first few chapters)
I felt the programming questions on my test were pretty hard and time consuming and I had only about 10 minutes left at the end. Problem for me was that, you are graded for 50 questions, but you need to answer 55 questions because you don’t know which ones are those 5 experimental (beta) ones and you have to solve them regardless.
So, how much should you prepare to pass the CCDH? I was always curiously interested in Hadoop and knew the general concepts already, but the CCDH really tests your fluency in all the areas listed on the Study Guide. So a good 3-4 weeks (few hours after work) did it for me. In a typical work environment, you have Google or several other sources to refer to or try out and of course in the comfort of your IDE, but this is a test and all of it needs to be in your head! Nevertheless, it was a good experience and I really learned a lot from the preparation and in the end I’m glad I passed it.
I would definitely recommend shelling out the $295, because that will really force you to prepare seriously. Good Luck!
Category: Hadoop