Redis persistent big key: elastic:bulk:initial:0:zset

This ZSET gets filled with arrays of the format ['Project', 123, 'project_123']. The set will contain projects, as well as their associations.

We do that from the Elastic::ProcessInitialBookkeepingService. Which we do when we create an ElasticIndexedProject.

This happens when we add projects to be indexed to the ApplicationSettings from the EE::ApplicationSettings::UpdateService. This could be done through the API or the UI.