26 March 2013

grails run-app and tomcat jmx

Want the standard Tomcat JMX exposed during development (grails run-app) ?

Add this to your Config.groovy:
grails.tomcat.jvmArgs=["-Dcom.sun.management.jmxremote", "-Dcom.sun.management.jmxremote.port=8099", "-Dcom.sun.management.jmxremote.ssl=false", "-Dcom.sun.management.jmxremote.authenticate=false"]

Fire up jconsole and hit localhost:8099.

</note to future self blog entry>

25 March 2013

Unit test your logging

I have a few log statements which are really important for me in production. Without them, I would be screwed when tracking whats actually going on. So I decided that this important code shouldn't be left out in the cold.

Here is a trivial example. Lets say the "Replacing address" log statement in the following code is really important when stuff hits the fan.

void setAddress(Address adr) {
  log.info "Replacing address ${this.address} with ${adr} on ${this}"
  this.address = adr
  log.debug "Updated{person} with new address"

def log = []
def collectLog = {String message -> log << message}
def finn = new Person(name:'finn', new Address(streetname:'homeless'))
finn.metaClass.log = [debug:collectLog, info:collectLog, error: collectLog]
finn.address = new Address(streetname:'Slottsplassen 1')
assert log.find {String msg -> msg.contains "Replacing address homeless with Slottsplassen 1 on Finn"}

The code turned out simpler than I feared when I initially decided I need to test my logging. Joy!