Re: Configuring multiple DataNodes

Since I use HikariCP (which I can recommend) I use a DataSourceFactory to configure my connections, something similar to the following pseudocode.
In this case you can read any available environment variables/properties to provide configuration.


public static ServerRuntime createServerRuntime() {
	return ServerRuntime
			.builder()
			.addConfig( "cayenne-project.xml" )
			.addModule( b -> b.bind( DataSourceFactory.class ).to( AppDataSourceFactory.class ) )
			.build();
}

private static class AppDataSourceFactory implements DataSourceFactory {

	@Override
	public DataSource getDataSource( DataNodeDescriptor dataNodeDescriptor ) throws Exception {
		final String dataNodeName = dataNodeDescriptor.getName();

		if( dataNodeName.equals( "somenode" ) ) {
			final HikariConfig config = new HikariConfig();
			config.setUsername( "someuser" );
			config.setPassword( "somepass" );
			config.setJdbcUrl( "someurl" );
			config.setMaximumPoolSize( 4 );
			return new HikariDataSource( config );
		}

		if( dataNodeName.equals( "othernode" ) ) {
			final HikariConfig config = new HikariConfig();
			config.setUsername( "otheruser" );
			config.setPassword( "otherpass" );
			config.setJdbcUrl( "otherurl" );
			config.setOtherStuff( ... );
			return new HikariDataSource( config );
		}

		throw new IllegalArgumentException( "Unknown dataNode: " + dataNodeName );
	}
}

Cheers,
- hugi


> On 23 Apr 2021, at 14:32, Tony Giaccone <[email protected]> wrote:
> 
> I have a datadomain with two datamaps, and two datasource each talking to a
> different database.
> 
> Right now, I have had the datasource configured in the config file, but I
> need to remove that and set it programmatically, from an environment
> variable.  Simple enough to do with a defauldata source, unclear how to do
> when you have multiple data sources and data nodes.
> 
> After browsing through the code and the app as it's running, it's unclear
> to me how to do this.
> 
> Does anyone know the secret sauce?
> 
> 
> 
> Tony