Please follow upgrade instructions for your deployment method:
3.0 Upgrade Notes
When starting Dremio (after upgrading to 3.0), most reflections enqueue a refresh job (typically, this happens only once).
This refresh occurs even if the reflection's refresh interval isn't due or the refection has "never refresh" set. Thereafter, if refresh intervals were set, then all reflections resume their usual refresh cycle. Monitor your reflection to ensure that the refresh completes successfully.
Enhanced Connector Framework
With this release, Dremio is utilizing improved relational connectors with the SQL Server and Postgres connectors. This provides enhanced performance and extensive push-down capabilities. This logic also considers UDTs (User Defined Types) to be unknown types and skips them.
When upgrading from the legacy version of these connectors to the new version has the potential of breaking reports if a UDT is in the report.
If your deployment has SSL enabled for the web server using custom certificates, you must add the following property to the dremio.conf file on all coordinators before starting Dremio after upgrade:
See the Web Server Encryption section in Using Wire Encryption for more information.