ERROR pool.ConnectionPool - Unable to create initial connections of pool - mysql

Question

I am Grails newbie. After doing some basic configuration in Datasource.groovy, my grails app fails to start. I get the below error
Error 2015-07-03 15:27:19,014 [localhost-startStop-1] ERROR pool.ConnectionPool - Unable to create initial connections of pool.
Message: Driver:org.h2.Driver#78f95cf6 returned null for URL:jdbc:mysql://localhost:3306/radb?createDatabaseIfNotExist=true
| Error 2015-07-03 15:27:19,854 [localhost-startStop-1] ERROR context.GrailsContextLoaderListener - Error initializing the application: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is java.lang.NullPointerException
The database radb exists. I have verified it
My Datasource.groovy file for reference as below
dataSource {
pooled = true
jmxExport = true
driverClassName = "org.h2.Driver"
dialect = "org.hibernate.dialect.MySQL5InnoDBDialect"
//username = "sa"
//password = ""
}
hibernate {
cache.use_second_level_cache = true
cache.use_query_cache = false
// cache.region.factory_class = 'net.sf.ehcache.hibernate.EhCacheRegionFactory' // Hibernate 3
cache.region.factory_class = 'org.hibernate.cache.ehcache.EhCacheRegionFactory' // Hibernate 4
singleSession = true // configure OSIV singleSession mode
flush.mode = 'manual' // OSIV session flush mode outside of transactional context
}
// environment specific settings
environments {
development {
dataSource {
dbCreate = "create-drop" // one of 'create', 'create-drop', 'update', 'validate', ''
url = "jdbc:mysql://localhost:3306/radb?createDatabaseIfNotExist=true"
username="root"
password="root"
logSql = true
}
}
test {
dataSource {
dbCreate = "update"
url = "jdbc:h2:mem:testDb;MVCC=TRUE;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
}
}
production {
dataSource {
dbCreate = "update"
url = "jdbc:h2:prodDb;MVCC=TRUE;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
properties {
// See http://grails.org/doc/latest/guide/conf.html#dataSource for documentation
jmxEnabled = true
initialSize = 5
maxActive = 50
minIdle = 5
maxIdle = 25
maxWait = 10000
maxAge = 10 * 60000
timeBetweenEvictionRunsMillis = 5000
minEvictableIdleTimeMillis = 60000
validationQuery = "SELECT 1"
validationQueryTimeout = 3
validationInterval = 15000
testOnBorrow = true
testWhileIdle = true
testOnReturn = false
jdbcInterceptors = "ConnectionState"
defaultTransactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED
}
}
}
}

Answer 1

your driverClassName is wrong. use the correct one for mysql (in the environments, e.g. com.mysql.jdbc.Driver), where you need mysql. right now you have:
default: driver=h2, dialect=mysql;
dev: url=mysql
prod: url=h2
you definetly want to clean this up. also make sure, you have the driver in your deps.