How to backup live mysql database?

I have 12 GB MySQL InnoDB Database with around 800 queries per second. No sooner I start 'mysqldump' over it to make backup I start getting '503' on my website.

How do I make backup of my live database without affecting the site performance?

try the following command since the database size is not small:

mysqldump -u USER -p --single-transaction --quick --lock-tables=false --all-databases (or) DATABASE | gzip > OUTPUT.gz

StackExchange Database Administrators Q#84223, answer score: 6