Ubuntu 12.04 and mysql does not start

Once you upgrade to Ubuntu 12.04 and if you had configured mysql to use UTF character set, the mysql server may not start.

This is due to the following deprecated parameters.

default-character-set=utf8
default-collation=utf8_unicode_ci

Replace the above parameters (they are normally in /etc/mysql/my.cnf)

character-set-server = utf8
collation-server = utf8_unicode_ci


Now restart mysql server using the command

sudo service mysql start

Good motivational video

http://www.youtube.com/watch?feature=player_embedded&v=hV63DbQ_qSc

ProGuard - A case to disable shrink

Assume you are obfuscating a jar in a web application (say you deploy it on machines where you want to protect from decompile+disassembling).

If you come across the error message "The output jar is empty. Did you specify the proper '-keep' options?" , disable shrinking (as you may not have a valid main method entry point in a web application.