preboot-issues.txt

There is a small period of time when migrations aren't recognized by rails during the deploy process and this causes errors.

- old code is running
- new code hits heroku
- heroku restart -> loads up the new code. takes 3ish minutes
- migration happens
- heroku restart -> loads up the new code again. takes 3ish minutes

With Preboot:
[old code ----------------------------------------------------]
  [new code ----------------------------------------------][********]
      [new db ------------------------------------------------------]
          [new code ------------------------------------------------]

Without Preboot:
          [------no response---]
[old code]
          [new cod|
           [new db]
                  [new code----]

I think the ideal situation would be that the first restart is skipped so that the rails app continues to hold on to it's existing db connection until the migration is done, and then the restart is fired.