title: SpringBoot Mysql Database Unable to open JDBC Connection for DDL execution
body: <p>I got my application running with using a local h2 database. Now I want to connect it to an online mysql database. But when trying to start the connection, I get <code>com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure</code> several times and in addition the following error:</p>
  
  <pre><code>org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1710) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:583) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1085) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:858) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:388) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1234) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  at quiz.QuizAppMain.main(QuizAppMain.java:16) [classes/:na]
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181]
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181]
  at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181]
  at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.0.RELEASE.jar:2.0.0.RELEASE]
  Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
  at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:970) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:895) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:388) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1769) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1706) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
  ... 21 common frames omitted
  Caused by: org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
  at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:69) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcConnection(ImprovedExtractionContextImpl.java:60) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcDatabaseMetaData(ImprovedExtractionContextImpl.java:67) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.getTables(InformationExtractorJdbcDatabaseMetaDataImpl.java:329) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.getTablesInformation(DatabaseInformationImpl.java:120) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:65) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.internal.SessionFactoryImpl.&lt;init&gt;(SessionFactoryImpl.java:312) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:460) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
  ... 28 common frames omitted
  Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
  </code></pre>
  
  <p>I added the following to my pom.xml:</p>
  
  <pre><code>    &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-data-jpa&lt;/artifactId&gt;
      &lt;/dependency&gt;
  
      &lt;dependency&gt;
          &lt;groupId&gt;javax.xml.bind&lt;/groupId&gt;
          &lt;artifactId&gt;jaxb-api&lt;/artifactId&gt;
      &lt;/dependency&gt;
  
      &lt;dependency&gt;
          &lt;groupId&gt;mysql&lt;/groupId&gt;
          &lt;artifactId&gt;mysql-connector-java&lt;/artifactId&gt;
          &lt;version&gt;5.1.6&lt;/version&gt;
      &lt;/dependency&gt;
  </code></pre>
  
  <p>And this to my application.properties:</p>
  
  <pre><code>spring.datasource.url=jdbc:mysql://my.url.net:port
  spring.datasource.username=username
  spring.datasource.password=password
  spring.datasource.name=dbname
  spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
  spring.jpa.hibernate.ddl-auto=update
  spring.datasource.driver-class-name=com.mysql.jdbc.Driver
  </code></pre>
  
  <p>When changing from h2 to mysql I did not do any changes on my sourcecode since I'm implementing the <code>CrudRepository</code> that should also work with mysql.</p>
  
  <p>Could you give me some hints what might be missing? I already checked similar questions here on stackoverflow, but after adding several solution approaches (e.g. adding the <code>hibernate.dialect</code> and <code>driver-class-name</code>) my application is still not working.</p>