Funnelback maintains two separate views of a collection:
is the view that people are currently querying;
is the previous/future view.The aim of the two views is to allow a collection to be updated without affecting query processing. Normally, the update process will perform all of its work in the offline view and once it has completed successfully, the two views are "swapped" allowing the new indexes to become available for queries.
There are a number of options in the collection's collection.cfg file that allows you to control whether the swap occurs. They include:
- changeover_percent will compare the number of documents in the old and new indexes; and
- vital_servers will check for hosts that must be indexed.