Upgrading Your First Database to Be Minimally Redundant

In Creating Your First Database, you create a simple NuoDB database called test whose domain includes one host with one storage manager (SM) and one transaction engine (TE) running on it. Suppose you are ready to deploy this database and have decided to start with a minimally redundant database, that is, one with two TEs and two SMs for data redundancy. Accomplishing this requires the following:

Configuring a Second Domain Host

To configure a minimally redundant database, you need at least two physical hosts available for the NuoDB processes to use. Also, there must be one broker running on each host in your domain. To start a broker on another host, you must install NuoDB software on the second host. See Installing NuoDB. When installing NuoDB on the second host, defer starting NuoDB services automatically.

After NuoDB is installed on the second host, edit the $NUODB_HOME/etc/default.properties file on the second host as follows:

Start (or restart) NuoDB services on the second host. See Starting and Stopping NuoDB Services. In the Automation Console on the first NuoDB host, you will see a second host appear on the Hosts page. For example:

Scaling the Database to Run on Two Hosts

NuoDB supplies four basic database templates that can be customized to suit most database needs. For details about the following built-in templates, see Using Database Templates.

You can scale the test database to use the Minimally Redundant templat while the test database is actively running.Start with the Databases page in the NuoDB Automation Console and click edit on the right:

The Edit Database dialog appears. In the Template field, switch from Single Host to Minimally Redundant. Leave all other options the same for now. Click Submit.

The Databases page reappears. It still shows status for the test database as ACTIVE. Click Hosts to see that there are two processes (1 TE and 1 SM) running on your original machine as well as two processes running on your second host machine. Your database is still up and running and had no interruption in service.