Users sometimes use Solr’s SWAP command when prototyping a local Solr instance. This uses a secondary core which can be read while the primary core is being rebuilt. Then they discover a problem when they move to SolrCloud on SearchStax.
SWAP vs. CREATEALIAS
Solr’s core swapping depends on its underlying SWAP feature, but SolrCloud uses the CREATEALIAS feature to do the same thing. Using SWAP with SolrCloud can damage your index.
SearchStax deployments are all SolrCloud deployments. Use CREATEALIAS with SearchStax.
For more information, see CREATEALIAS: Create or Modify an Alias for a Collection.