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In Automation Console, to create a database:
Before doing anything else, the Create Managed Database dialog prompts for a database name, a DBA username, and a DBA password.
The next step is to choose one of the four NuoDB provided templates (see Using Database Templates).
A Single Host database is started on a given host, hence if you choose the Single Host template, you will be prompted to pick one of the hosts in your domain:
Minimally Redundant and Multi Host Databases require that you select a region in which to run; any host in that region will be considered a candidate to start your SM and TE processes:
A Geo-distributed database will run in all regions, hence no host nor region selection is required.
The Default Database Options>> panel allows you to add/edit the default database options that are used for all processes for this database. The default database options that are already set will vary based on which template you have chosen. It is not required that you modify anything in this panel; you may just accept the defaults.
If you wish to add a default database option, click the plus sign and enter a key/value pair where the key is the option name and the value is its setting. See Database Options for more information.
Caution: The option must be valid. You can add additional database options using name/value pairs but note that the option must be a valid option otherwise the process (TE or SM) will fail to start.
The Process Group Options>> panel allows you to add/edit the database options per process group in the database. It is not required that you enter anything in this panel. For each region in your database, there are two (2) process groups, one called SMs (storage managers) and one called TEs (transaction engines). If desired, you can specify database options per process group, that is, per all storage managers or all transaction engines in one or all regions. Choose which process group.
And specify the key/value pair where the key is the database option and the value is its setting:
Note: Process group options take precedence over default database options.
The Requirements>> panel allows you to edit the minimum and maximum requirements for the SMs and TEs process groups. This panel is not visible if the chosen template is Single Host. Again, for each region in your database, there are two (2) process groups, one called SMs (storage managers) and one called TEs (transaction engines). Both groups define a minimum and maximum value for the number of processes in the database. It is not required that you modify anything in this panel; you may just accept the defaults. Note: The enforcer will start a maximum of one TE and one SM per database per host.
This is where it gets exciting. Again, please take a quick look at the Using Database Templates page.
The NuoDB out-of-the-box templates all have the concept of two process groups per region, SMs and TEs. These groups can be used in order to opt into host tag constraints. The constraints we define below say to only consider hosts where a tag name Storefront exists (ex:). If no such host exists, or, per the requirements above, less than two such hosts exist, then the scale-out can not complete and the Database will remain in an UNMET state.
Of course tag constraints can create situations where the required SM and TE processes cannot be started for the database. This can result in the database either not starting at all or being marked as UNMET. Tag constraints apply to database creation as well, not just scale-out. In the case of unmet constraints, the Automation Console shows an error like this:
See Setting Host Tags for more information on how to specify a tag for a host.