Using an external database for cluster services

Cloudbreak allows you to register an existing RDBMS instance as an external source to be used for a database for certain services. After you register the RDBMS with Cloudbreak, you can use it for multiple clusters.

Supported databases

If you would like to use an external database for one of the components that support it, you may use the following database types and versions:

External database options

Cloudbreak includes the following external database options:

During cluster create, Cloudbreak checks whether the JDBC properties are present in the blueprint:

Example 1: Built-in type Hive

In this scenario, you start up with a standard blueprint, and Cloudbreak injects the JDBC properties into the blueprint.

1. Register an existing external database of "Hive" type (built-in type):

   

   Property variable	Example value
   rds.hive.connectionString	jdbc:postgresql://ec2-54-159-202-231.compute-1.amazonaws.com:5432/hive
   rds.hive.connectionDriver	org.postgresql.Driver
   rds.hive.connectionUserName	myuser
   rds.hive.connectionPassword	Hadoop123!
   rds.hive.fancyName	PostgreSQL
   rds.hive.databaseType	postgres

2. Create a cluster by using a standard blueprint (i.e. one without JDBC related variables) and by attaching the external Hive database configuration.

3. Upon cluster create, Hive JDBC properties will be injected into the blueprint according to the following template:

   ...
   "hive-site": {
   "properties": {
     "javax.jdo.option.ConnectionURL": "{{{ rds.hive.connectionString }}}",
     "javax.jdo.option.ConnectionDriverName": "{{{ rds.hive.connectionDriver }}}",
     "javax.jdo.option.ConnectionUserName": "{{{ rds.hive.connectionUserName }}}",
     "javax.jdo.option.ConnectionPassword": "{{{ rds.hive.connectionPassword }}}"
   }
     },
     "hive-env" : {
   "properties" : {
     "hive_database" : "Existing {{{ rds.hive.fancyName}}} Database",
     "hive_database_type" : "{{{ rds.hive.databaseType }}}"
   }
   }
   ...

Example 2: Other type

In this scenario, you start up with a special blueprint including JDBC property variables, and Cloudbreak replaces JDBC-related property variables in the blueprint.

1. Prepare a blueprint blueprint that includes property variables. Use mustache template syntax. For example:

   ...
   "test-site": {
     "properties": {
      "javax.jdo.option.ConnectionURL":"{{rds.test.connectionString}}"
     }
   ...

2. Register an existing external database of some "Other" type. For example:

   

   Property variable	Example value
   rds.hive.connectionString	ec2-54-159-202-231.compute-1.amazonaws.com:5432/hive
   rds.hive.connectionDriver	org.postgresql.Driver
   rds.hive.connectionUserName	myuser
   rds.hive.connectionPassword	Hadoop123!
   rds.hive.subprotocol	postgres
   rds.hive.databaseEngine	POSTGRES

3. Create a cluster by using your custom blueprint and by attaching the external database configuration.

4. Upon cluster create, Cloudbreak replaces JDBC-related property variables in the blueprint.

Related links
Mustache template syntax

Creating a template blueprint for RDMBS

In order to use an external RDBMS for some component other than the built-in components, you must include JDBC property variables in your blueprint. You must use mustache template syntax. See Example 2: Other type for an example configuration.

Related links
Creating a template blueprint
Mustache template syntax (External)

Register an external database

You must create the external RDBMS instance and database prior to registering it with Cloudbreak. Once you have it ready, you can:

1. Register it in Cloudbreak web UI or CLI.
2. Use it with one or more clusters. Once registered, the database will now show up in the list of available databases when creating a cluster under advanced External Sources > Configure Databases.

Prerequisites

If you are planning to use an external MySQL or Oracle database, you must download the JDBC connector's JAR file and place it in a location available to the cluster host on which Ambari is installed. The steps below require that you provide the URL to the JDBC connector's JAR file.

If you are using your own custom image, you may place the JDBC connector's JAR file directly on the machine as part of the image burning process.

Steps

1. From the navigation pane, select External Sources > Database Configurations.
2. Select Register Database Configuration.

3. Provide the following information:

   Parameter	Description
   Name	Enter the name to use when registering this database to Cloudbreak. This is not the database name.
   Type	Select the service for which you would like to use the external database. If you selected "Other", you must provide a special blueprint.
   JDBC Connection	Select the database type and enter the JDBC connection string (HOST:PORT/DB_NAME).
   Connector's JAR URL	(MySQL and Oracle only) Provide a URL to the JDBC connector's JAR file. The JAR file must be hosted in a location accessible to the cluster host on which Ambari is installed. At cluster creation time, Cloudbreak places the JAR file in the /opts/jdbc-drivers directory. You do not need to provide the "Connector's JAR URL if you are using a custom image and the JAR file was either manually placed on the VM as part of custom image burning or it was placed there by using a recipe.
   Username	Enter the JDBC connection username.
   Password	Enter the JDBC connection password.

4. Click Test Connection to validate and test the RDS connection information.

   Note

   The Test Connection option:

   • Does not work when an external authentication source uses LDAPS with a self-signed certificate.
   • Might not work if Cloudbreak instance cannot reach the LDAP server instance.

   In these cases, ignore the error and proceed with cluster installation.

5. Once your settings are validated and working, click REGISTER to save the configuration.

6. The database will now show up on the list of available databases when creating a cluster under advanced External Sources > Configure Databases. You can select it and click Attach each time you would like to use it for a cluster.