The Transactional Activation module ensures synchronization of content between multiple public instances.
The module extends the one-subscriber of the Community Edition by providing parallel publishing to up to 10 public instances. Publishing to multiple subscribers is encapsulated in a single transaction. This means that if one of the public instances is down, content will not be published to any of them.
Transactional publishing works the same way for unpublishing. It also works the same way whether publishing is invoked directly or via an approval workflow.