You didn’t post what kind of environment you are running in, but I assume it’s a custom one or Tomcat/Jetty? You should configure a connection pool like described here: https://docs.jboss.org/hibernate/stable/orm/userguide/html_single/Hibernate_User_Guide.html#database-connectionprovider-datasource or even better, use an environment like a Java EE server(Wildfly, Payara) that comes with connection pooling configuration out of the box.