Encoding problems in Grails

If there are problems with charsets while submitting forms in Tomcat, and headers for responses/requests looks correct, you can try to fix it by adding URIEncoding="UTF-8" into your server.xml. This fixed things nicely to me. Read more about it at http://wiki.apache.org/tomcat/FAQ/CharacterEncoding.

MySQL dump without locking tables

If you just do MySQL dump without any parameters, it locks tables and consumes a lot of memory. If you want to avoid it and you have InnoDB, best way to do it is to add single-transaction (run in single transaction) and q (dump one row at once) properties, for example like:

mysqldump -q --single-transaction -u login -ppassword db > dump.sql

Time difference with DST

If you need to calculate time difference that include Daylight Saving Time in Groovy, it is super simple with groovy.time.TimeCategory:

TimeDuration hours = TimeCategory.minus(end.time, start.time)