Can anyone please tell me that, does HCatalog require installation before using? Or it can be used just as a jar file?
I have Cloudera running on a VM, and I can use HCatalog for my MR job, Pig, Hive with no problem. And I thought the same MR code would work with another hadoop installed platform, but obviously it's not the case, exception thrown on the HCatInputFormat.setInput(). When I use Pig -useHCatalog, I'ved been prompted that the usage was wrong, meaning that it didn't know what's -useHCatalog as a parameter.
Didn't thought about this before as have been using HCatalog on Cloudera...
Yes, you need to install and start HCatalog server. HCatalog should come with the latest Hive tar package.
Check here of Apache Hive documentation for details,
Basically you need to,
Setup MySQL database for HCatalog
Run server install script
share/hcatalog/scripts/hcat_server_install.sh -r root -d dbroot -h hadoop_home -p portnum
Start the HCatalog server
export HIVE_HOME=hive_home $HIVE_HOME/sbin/hcat_server.sh start