Upgrading Pier 2 to Pier 3

Successfully upgraded from Pier 2 to Pier 3 recently - several lessons learned:

• Publish early, publish often - do not let nice to have planned changes hold up a break-fix - it is better to write them both to the repository as soon as they are ready
• It is best to run the test Pier image on a different port - this can be changed in Pier 3 with:

  ZnZincServerAdaptor allInstances size = 1 ifFalse: [ self halt: 'Not sure what to do about more than one.' ].
  ZnZincServerAdaptor allInstances anyOne isRunning.
  ZnZincServerAdaptor allInstances anyOne stop.
  ZnZincServerAdaptor allInstances anyOne port: 8888.
  ZnZincServerAdaptor allInstances anyOne start.