Upgrading from Previous Releases
If you have previously installed MarkLogic on a machine, you must uninstall the old release before proceeding with the new installation. For information on removing the software, see Removing MarkLogic or the Installation Guide from the previous release.
If you are upgrading a cluster to a new release, see Upgrading a Cluster to a New Maintenance Release of MarkLogic Server in the Scalability, Availability and Failover Guide. The Security database and the Schemas database must be on the same host, and that host should be the first host you upgrade when upgrading a cluster.
Warning
MarkLogic Server does not support downgrades. Once you have upgraded to a later release, you cannot downgrade to a previous version. To retain the option to restore to a previous version of MarkLogic Server, make a complete backup of your content and security databases before upgrading.