We use Liquibase as database refactoring tool in a cloud service, and would now like to employ it to do some lightweight data migration, which would be realized as CustomTaskChange and would take just a few seconds. This data migration is 'nice to have' but it is by no means mandatory for the service to function properly - if it fails for some reason, the change set should just be skipped, the service started nevertheless, and the change set retried during the next restart of the service until it finally succeeds. So, errors when executing the change set should be ignored but the set marked as ran only after it actually ran successfully once.
We wonder how we could implement this kind of behavior using Liquibase: The <changeSet> attribute failOnError="false" continues in case of an error but according to documentation and an answer given by Nathan Voxland here at StackOverflow it always marks the change set as ran - hence Liquibase wouldn't retry to execute it during the next startup of the service. The <preConditions> attribute onFail seems to be concerned only with failing preconditions so startup would still fail in case of an error when setting onFail to, say, CONTINUE.
Is there any other option / attribute that we overlooked or a recommended fashion to solve this kind of situation?
You may be able to achieve the "retry until successful" behaviour if you implement the optional data migration inside the code of a custom precondition. Then, you could configure
onFailof that precondition toCONTINUEwhich will give you the behaviour you want (source):I'm not entirely sure if implementing the migration in the precondition code is technically possible – because it certainly wasn't meant for such things. And you also may want to verify that the custom precondition is not executed again once the patch set has been marked as ran.