Upgrading the Database Protocol

A new version of NuoDB database software may introduce a new version of the database protocol. For new releases that introduce a new database protocol version, the database will not be upgraded to the new version until the database protocol version is upgraded.

Changes to the database protocol are sometimes necessary to support new features or fix issues. The version of the database protocol used by the database processes is stored in the NuoDB Archive so that when a new database is started, the processes know which protocol to communicate with.

To successfully upgrade the database protocol, you must do the following:

  1. Confirm whether a new database protocol version is available.
  2. Upgrade to the new database protocol.
  3. Start a Transaction Engine (TE).

Upgrading the Database Protocol Instructions

Note: Before the database protocol can be upgraded, all of the database hosts must have the new software version installed. If all of the existing database processes have not been upgraded to the new software version, the show database version command returns only “Available Upgrade Versions: None”.

1. Confirming Whether a new Database Protocol Version is Available

After upgrading database software, it may be necessary to upgrade the database protocol. To check to see if a new database protocol version is available, run NuoDB Manager's show database version command.

nuodb [test] > show database version database test details false
Database Version: 4.0
Available Upgrade Versions: None
nuodb [test] > show database version database test details false
Database Version: 3.2.2
Available Upgrade Versions: 3.3

2. Upgrading to the New Database Protocol

To upgrade to a new database protocol, run the upgrade database command:

nuodb [test] > upgrade database test version 3.
Upgrading database test to version 3.3...
Upgrade complete

The effects of this command will be immediately synchronized to the archive:

3. Starting a Transaction Engine

At this point, although an Upgrade complete message is returned, the upgrade process is not complete until you restart the TE with the lowest nodeId.

Note: After the database protocol version has been upgraded, the NuoDB Archive cannot be used with a previous NuoDB software version that only supports the previous database protocol version. As a result, downgrading after the database protocol version will require restoring a backup of the database. For more information on downgrading, see Downgrading to a Previous Release.