How to set initial connections of a dynamic data source - spring-boot

Question

I have a multi-tenant application with multiple datasources. The exact url which its connecting is set by runtime, depending on a request parameter. When I make a request at default 10 database-connections are created. With multiple datasources this fast sums up to a lot of connections. So I want to lower that number and also close the connections after a certain time.
My Configuration Class:
#Configuration
#EnableTransactionManagement
#EnableJpaRepositories(
basePackages = "com.example.demo",
entityManagerFactoryRef = "multiEntityManager",
transactionManagerRef = "multiTransactionManager"
)
public class PersistenceConfiguration extends WebMvcConfigurerAdapter {
private final String PACKAGE_SCAN = "com.example.demo";
//datasources
#Primary
#Bean(name = "COMP1")
public DataSource company1DS() {
return DataSourceBuilder.create()
.username("root")
.password("password")
.url("jdbc:mysql://81.123.456.789:3306/company1")
.build();
}
#Bean(name = "COMP2")
public DataSource company2DS() {
return DataSourceBuilder.create()
.username("root")
.password("password")
.url("jdbc:mysql://81.123.456.789:3306/company2")
.build();
}
#Bean(name = "multiRoutingDataSource")
public DataSource multiRoutingDataSource() {
Map<Object, Object> targetDataSources = new HashMap<>();
targetDataSources.put("COMP1", company1DS());
targetDataSources.put("COMP2", company2DS());
MultiRoutingDataSource multiRoutingDataSource = new MultiRoutingDataSource();
multiRoutingDataSource.setDefaultTargetDataSource(company1DS());
multiRoutingDataSource.setTargetDataSources(targetDataSources);
return multiRoutingDataSource;
}
#Bean(name = "multiEntityManager")
public LocalContainerEntityManagerFactoryBean multiEntityManager() {
LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
em.setDataSource(multiRoutingDataSource());
em.setPackagesToScan(PACKAGE_SCAN);
HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
em.setJpaVendorAdapter(vendorAdapter);
em.setJpaProperties(hibernateProperties());
return em;
}
#Bean(name = "multiTransactionManager")
public PlatformTransactionManager multiTransactionManager() {
JpaTransactionManager transactionManager
= new JpaTransactionManager();
transactionManager.setEntityManagerFactory(
multiEntityManager().getObject());
return transactionManager;
}
#Primary
#Bean(name = "dbSessionFactory")
public LocalSessionFactoryBean dbSessionFactory() {
LocalSessionFactoryBean sessionFactoryBean = new LocalSessionFactoryBean();
sessionFactoryBean.setDataSource(multiRoutingDataSource());
sessionFactoryBean.setPackagesToScan(PACKAGE_SCAN);
sessionFactoryBean.setHibernateProperties(hibernateProperties());
return sessionFactoryBean;
}
private Properties hibernateProperties() {
Properties properties = new Properties();
return properties;
}
}
What I already tried:
I tried to change the values in the application.properties file like so:
spring.datasource.maxActive=2
spring.datasource.minIdle=2
spring.datasource.maxIdle=5
spring.datasource.initialSize=2
I tried to change the properties the dynamic way (PersistenceConfiguration.hibernateProperties()):
private Properties hibernateProperties() {
Properties properties = new Properties();
properties.put("spring.datasource.maxActive",2);
properties.put("spring.datasource.minIdle",2);
properties.put("spring.datasource.maxIdle",5);
properties.put("spring.datasource.initialSize",2);
return properties;
}
But it seems that no properties get applied. When I show SHOW GLOBAL STATUS LIKE 'Connections'; in the MySQL workbench, I always get 10 more connections after I made a request from a new datasource.
If there is any important information missing, please let me know and I will add it.
I really appreciate your effort,
Greetings Alexander
EDIT
Since spring.datasource.max-active=2 is not valid, I also tried all the following in application-properties, as well as in the hibernateProperties();
spring.datasource.hikari.maximum-pool-size=2
spring.datasource.tomcat.initial-size=2
spring.datasource.tomcat.max-idle=2
private Properties hibernateProperties() {
Properties properties = new Properties();
properties.put("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
properties.put("spring.datasource.hikari.maximum-pool-size",2);
properties.put("spring.datasource.tomcat.initial-size",2);
properties.put("spring.datasource.tomcat.max-idle",2);
properties.setProperty("spring.datasource.hikari.maximum-pool-size","2");
properties.setProperty("spring.datasource.tomcat.initial-size","2");
properties.setProperty("spring.datasource.tomcat.max-idle","2");
return properties;
}
Nothing changed a thing