Additional database-related settings

All the settings below can be added at the schema level. For example, the statistics database can become very large over time, so you may want to use a separate server for the statistics database.

Connection and pool parameters can be added to the configuration file. In such a case, all other schemas would use the default connection pool.

Listing 1. Unblu database configuration reference

com.unblu.storage.database.platform=Auto
com.unblu.storage.database.driver=org.h2.Driver
com.unblu.storage.database.url=jdbc\:h2\:mem\:unblu
com.unblu.storage.database.jdbcProperties=
com.unblu.storage.database.user=unblu
com.unblu.storage.database.password=secret
com.unblu.storage.database.schema=unblu
com.unblu.storage.database.liquibaseSchema=
com.unblu.storage.database.adminJdbcProperties=
com.unblu.storage.database.adminUser=
com.unblu.storage.database.adminPassword=
com.unblu.storage.database.poolMax=50
com.unblu.storage.database.poolMinIdle=
com.unblu.storage.database.adminUser=
com.unblu.storage.database.adminPassword=

Connection pool

The default JDBC connection pool is HikariCP. It provides improvements in both speed and stability compared to the deprecated EclipseLink connection pool:

Connections are closed when not used for a longer period.
Connections are validated before using java.sql.Connection.isValid(int) provided by the JDBC Driver. For more information refer to the Java documentation.
New connections are opened proactively, not just on demand.

A Grafana dashboard called "Database (HikariCP)" visualizing all HikariCP metrics is automatically deployed with every Unblu cluster installation.

Listing 2. HikariCP default configuration

# Database connection pool
com.unblu.storage.database.datasourceFactory=HIKARI
com.unblu.storage.database.poolMax=20 (1)
com.unblu.storage.database.poolMinIdle=20 (2)

1	Maximum number of connections in the pool.
2	Minimum number of connections that should be idle, new connections are added to the pools when connections are busy up to the configured maximum number of connections.

The configuration above reflects the default settings. Only add a connection pool configuration if you want to deviate from this default. For production setups, the following values may be more appropriate:

com.unblu.storage.database.poolMax=60
com.unblu.storage.database.poolMinIdle=60

Instead of the approaches listed in this section, you can also use a data source provided by the application server. For instructions, refer to Managing connections to the database server using JNDI datasource.