Configuring hikari connection pool

Question

I have following settings for my database (I have multiple databases, so they are configured in spring.datasource hierarchy.

spring:
  datasource:
    db-write:
      url: jdbc:sqlserver://whatever.database.windows.net:1433;database=dbname;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;
      username: 'myusername'
      password: 'mynotsosecretpassword'
      driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver

Then I am configuring my datasource here

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.datasources.dbwrite.repository",
        entityManagerFactoryRef = "entityManagerFactoryDbWrite",
        transactionManagerRef= "transactionManagerDbWrite"
)
public class DataSourceConfigurationDbWrite {
    @Bean
    @Primary
    @ConfigurationProperties("spring.datasource.db-write")
    public DataSourceProperties dataSourcePropertiesDbWrite() {
        return new DataSourceProperties();
    }

    @Bean
    @Primary
    @ConfigurationProperties("spring.datasource.db-write.configuration")
    public DataSource dataSourceDbWrite() {
        return dataSourcePropertiesDbWrite().initializeDataSourceBuilder()
                .type(HikariDataSource.class).build();
    }

    @Primary
    @Bean(name = "entityManagerFactoryDbWrite")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryDbWrite(EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(dataSourceDbWrite())
                .packages("com.datasources.dbwrite.models")
                .build();
    }

    @Primary
    @Bean
    public PlatformTransactionManager transactionManagerDbWrite(
            final @Qualifier("entityManagerFactoryDbWrite") LocalContainerEntityManagerFactoryBean entityManagerFactoryDbWrite) {
        return new JpaTransactionManager(Objects.requireNonNull(entityManagerFactoryDbWrite.getObject()));
    }
}

I am configuring my hikari datasource in dataSourceDbWrite method based on the properties i read in dataSourcePropertiesDbWrite method. I believe i need to configure properties in specific hierarchy so that dataSourceDbWrite method can easily detect which properties are needed for hikari . Is that correct?

What that hierarchy would be?

Moreover, how can and where can i find what properties i can configure for hikari? connection-timeout? connection pool size etc?

Answer 1

Me personally prefer application.yml than code to configurate Hikari:

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: {JDBC URL}
    username: {USERNAME}
    password: {PASSWORD}
    type: com.zaxxer.hikari.HikariDataSource
    hikari:
      minimum-idle: 5
      idle-timeout: 600000
      maximum-pool-size: 10
      auto-commit: true
      pool-name: HikariCorePool
      max-lifetime: 1800000
      connection-timeout: 30000
      connection-test-query: select * from information_schema.tables limit 1

(BTW, that piece of configuration was originally writen by a colleague years ago. We didn't change it and just copy-and-paste into any new projects those years.😆)

If you want to check out all configurable fields, those spring.datasource.hikari.* keys in org.springframework.boot:spring-boot-autoconfigure:{VERSION}/META-INF/spring/spring-configuration-metadata.json may could help.

And javadoc in com.zaxxer.hikari.HikariConfigMXBean could help too.

Answer 2

See example in article , the properties hierarchy are according to @ConfigurationProperties 's value

If we want to configure Hikari, we just need to add a @ConfigurationProperties to the data source definition:

 @Bean @ConfigurationProperties("spring.datasource.todos.hikari") public DataSource todosDataSource() { return todosDataSourceProperties() .initializeDataSourceBuilder() .build(); }

Then, we can insert the following lines into the application.properties file:

 spring.datasource.todos.hikari.connectionTimeout=30000 spring.datasource.todos.hikari.idleTimeout=600000 spring.datasource.todos.hikari.maxLifetime=1800000

See relevant hikari's spring properties

spring.datasource.hikari.connection-timeout
spring.datasource.hikari.data-source-class-name
spring.datasource.hikari.data-source-properties
spring.datasource.hikari.driver-class-name
spring.datasource.hikari.idle-timeout
spring.datasource.hikari.initialization-fail-timeout
spring.datasource.hikari.jdbc-url
spring.datasource.hikari.leak-detection-threshold
spring.datasource.hikari.login-timeout
spring.datasource.hikari.max-lifetime
spring.datasource.hikari.maximum-pool-size
spring.datasource.hikari.minimum-idle
spring.datasource.hikari.validation-timeout

And explanation on each property in HikariCP , for example

connectionTimeout This property controls the maximum number of milliseconds that a client (that's you) will wait for a connection from the pool. If this time is exceeded without a connection becoming available, a SQLException will be thrown. Lowest acceptable connection timeout is 250 ms. Default: 30000 (30 seconds)

Notice that camelCase hikari properties (connectionTimeout) is shown as snake-case in spring (connection-timeout)