The configuration entered is not valid. A database connection could not be established. Please check your configuration and try again.
	com.atlassian.stash.internal.db.DefaultDatabaseManager.validateConfiguration(DefaultDatabaseManager.java:222)
	com.atlassian.stash.internal.db.DefaultDatabaseManager.prepareDatabase(DefaultDatabaseManager.java:175)
	com.atlassian.stash.internal.maintenance.SpringMaintenanceTaskFactory.migrationTask(SpringMaintenanceTaskFactory.java:139)
	...
Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)
	com.atlassian.stash.internal.db.DefaultDatabaseValidator.validate(DefaultDatabaseValidator.java:44)
	com.atlassian.stash.internal.db.DefaultDatabaseManager.validateConfiguration(DefaultDatabaseManager.java:219)
	...
Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
	sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
	...
connect timed out
	java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
	java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
	java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
	...