The Crawl State is the representation of the progress made by an in progress crawl. By using the crawl state Aspire is able to distribute the processing tasks between multiple Aspire nodes, as well as pausing/resuming crawls. In order for it to be synchronized between multiple Aspire nodes, as well as preserve the state on restarts, it needs to be stored in an external database.
As of Aspire 4.0, we support two different databases: