Error pool.ConnectionPool – Unable to create initital connections of pool

database-connectiondatasourcegrails

I'm following the application development in Grails titled TekDays from the book "Grails 2 – A quick start quide". As I started to configure DataSource, I encountered a problem of establishing the database connection. I have no idea what is the cause since the steps that I'm following is pretty much very clear. The source codes and errors are written below.

DataSource.groovy:

dataSource {
pooled = true
jmxExport = true
driverClassName = "org.h2.Driver"
username = "dave"
password = "1234"
}
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 = "update" // one of 'create', 'create-drop', 'update', 'validate', ''
            url = "jdbc:mysql//localhost:3306/tekdays"
        }
    }
    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
            }
        }
    }
}

BuildConfig:

grails.servlet.version = "3.0" // Change depending on target container     compliance (2.5 or 3.0)
grails.project.class.dir = "target/classes"
grails.project.test.class.dir = "target/test-classes"
grails.project.test.reports.dir = "target/test-reports"
grails.project.work.dir = "target/work"
grails.project.target.level = 1.6
grails.project.source.level = 1.6
//grails.project.war.file = "target/${appName}-${appVersion}.war"

grails.project.fork = [
    // configure settings for compilation JVM, note that if you alter the Groovy version forked compilation is required
    //  compile: [maxMemory: 256, minMemory: 64, debug: false, maxPerm: 256, daemon:true],

    // configure settings for the test-app JVM, uses the daemon by default
    test: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256, daemon:true],
    // configure settings for the run-app JVM
    run: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256, forkReserve:false],
    // configure settings for the run-war JVM
    war: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256, forkReserve:false],
    // configure settings for the Console UI JVM
    console: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256]
]

grails.project.dependency.resolver = "maven" // or ivy
grails.project.dependency.resolution = {
    // inherit Grails' default dependencies
    inherits("global") {
        // specify dependency exclusions here; for example, uncomment this to disable ehcache:
        // excludes 'ehcache'
    }
    log "error" // log level of Ivy resolver, either 'error', 'warn',   'info', 'debug' or 'verbose'
    checksums true // Whether to verify checksums on resolve
    legacyResolve false // whether to do a secondary resolve on plugin     installation, not advised and here for backwards compatibility

    repositories {
        inherits true // Whether to inherit repository definitions from plugins

        grailsPlugins()
        grailsHome()
        mavenLocal()
        grailsCentral()
        mavenCentral()
        // uncomment these (or add new ones) to enable remote dependency resolution from public Maven repositories
        //mavenRepo "http://repository.codehaus.org"
        //mavenRepo "http://download.java.net/maven/2/"
        //mavenRepo "http://repository.jboss.com/maven2/"
    }

    dependencies {
        // specify dependencies here under either 'build', 'compile',     'runtime', 'test' or 'provided' scopes e.g.
         runtime 'mysql:mysql-connector-java:5.1.24'
        // runtime 'org.postgresql:postgresql:9.3-1101-jdbc41'
        //test "org.grails:grails-datastore-test-support:1.0.2-grails-2.4"
    }

    plugins {
        // plugins for the build system only
        build ":tomcat:7.0.55"

        // plugins for the compile step
        compile ":scaffolding:2.1.2"
        compile ':cache:1.1.8'
        compile ":asset-pipeline:1.9.9"

        // plugins needed at runtime but not for compilation
        runtime ":hibernate:3.6.10.18" // or ":hibernate:3.6.10.18" hibernate4:4.3.6.1
        runtime ":database-migration:1.4.0"
        runtime ":jquery:1.11.1"

        // Uncomment these to enable additional asset-pipeline capabilities
        //compile ":sass-asset-pipeline:1.9.0"
        //compile ":less-asset-pipeline:1.10.0"
        //compile ":coffee-asset-pipeline:1.8.0"
        //compile ":handlebars-asset-pipeline:1.3.0.3"
    }
}

and finally the BootStrap.groovy

import com.tekdays.*

class BootStrap {

    def init = { servletContext ->

        //if(!TekEvent.get(1)){
    new TekUser(fullName: 'John Doe' ,
            userName: 'jdoe' ,
        password: 't0ps3cr3t' ,
        email: 'jdoe@johnsgroovyshop.com' ,
        website: 'blog.johnsgroovyshop.com' ,
        bio: '''John has been programming for over 40 years.     He has worked with every programming language known to man and has settle on Groovy.
        In his spare time, John dabbles in astro physics and plays shuffleboard.''').save()

    new TekUser(fullName: 'John Deere' ,
        userName: 'tractorman' ,
        password: 't0ps3cr3t' ,
        email: 'john.deere@porkproducers.org' ,
        website: 'www.perl.porkproducers.org' ,
        bio: '''John is a top notch Perl programmer and a pretty good hand around the farm.  If he can't program it he
            can plow it!''').save()

    def event1 = new TekEvent(name: 'Gateway Code Camp' ,
         city: 'Saint Louis, MO' ,
         organizer: TekUser.findByFullName('John Doe') ,
         venue: 'TBD' ,
         startDate: new Date('02/02/2015') ,
         endDate: new Date('02/05/2015') ,
         description: '''This conference will bring coders from across platforms, languages, and industries
                                     together for an exciting day of tips, tricks, and tech!''').save()


    def event2 = new TekEvent(name: 'Perl Before Swine' ,
         city: 'Austin, MN' ,
         organizer: TekUser.findByFullName('John Deere') ,
         venue: 'SPAM Museum' ,
         startDate: new Date('06/02/2015') ,
         endDate: new Date('10/05/2015') ,
         description: '''Join the Perl programmers of the Pork Producers of America as we hone our skills and ham it up a bit.
                                        You can show off your programming chops while trying to win a year's supply of pork chops in our programming
                                        challenge.''').save()


    def g1 = TekEvent.findByName('Gateway Code Camp')
    g1.addToVolunteers(new TekUser(fullName: 'Sarah Martin' ,
            userName: 'sarah' ,
            password: '54321' ,
            email: 'sarah@matinworld.com' ,
            website: 'www.martinworld.com' ,
            bio: 'Web designer and Grails afficianado.'))
    g1.addToVolunteers(new TekUser(fullName: 'Bill Smith' ,
            userName: 'Mr_Smith' ,
            password: '12345' ,
                email: 'mrbill@email.com' ,
                website: 'www.mrbillswebsite.com' ,
            bio: 'Software developer, claymation artist.'))

    g1.addToRespondents('ben@grailsmail.com')
    g1.addToRespondents('zachary@linuxgurus.org')
    g1.addToRespondents('solomon@bootstrapwelding.com')

    def s1 = new Sponsor(name:'Contegix',
                 website:'http://www.contegix.com',
             description:'Beyond Managed Hosting for your Enterprise').save()

    def s2 = new Sponsor(name:'Object Computing Incorporated',
                     website:'http://www.ociweb.com',
                     description:'An 00 Software Engineering Company').save()

    def sp1 = new Sponsorship(event:g1,
                          sponsor:s1,
                      contributionType:'Other',
                      description:'Cool T-Shirts').save()

    def sp2 = new Sponsorship(event:g1,
                          sponsor:s2,
                          contributionType:'Venue',
                  description:'Will be paying for the Moscone').save()

    g1.save()
    //} 
    }

    def destroy = {
    }
}

Error:

Error |
2015-02-02 11:58:40,431 [localhost-startStop-1] ERROR         pool.ConnectionPool  - Unable to create initial connections of pool.
Message: Driver:org.h2.Driver@3fdec6a5 returned null for     URL:jdbc:mysql//localho
st:3306/tekdays
    Line | Method
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Error |
2015-02-02 11:58:40,533 [localhost-startStop-1] ERROR     pool.ConnectionPool  - Una
ble to create initial connections of pool.
Message: Driver:org.h2.Driver@68e17b43 returned null for     URL:jdbc:mysql//localho
st:3306/tekdays
    Line | Method
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Error |
2015-02-02 11:58:40,642 [localhost-startStop-1] ERROR     pool.ConnectionPool  - Una
ble to create initial connections of pool.
Message: Driver:org.h2.Driver@317f67a9 returned null for     URL:jdbc:mysql//localho
st:3306/tekdays
    Line | Method
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Error |
2015-02-02 11:58:40,665 [localhost-startStop-1] ERROR     context.GrailsContextLoade
rListener  - Error initializing the application: Error creating bean     with name '
transactionManagerPostProcessor': Initialization of bean failed; nested     exceptio
n is org.springframework.beans.factory.BeanCreationException: Error     creating bea
n with name 'transactionManager': Cannot resolve reference to bean     'sessionFacto
 ry' while setting bean property 'sessionFactory'; nested exception is     org.spring
framework.beans.factory.BeanCreationException: Error creating bean with    name 'se
ssionFactory': Cannot resolve reference to bean 'hibernateProperties'     while sett
ing bean property 'hibernateProperties'; nested exception is     org.springframework.beans.factory.BeanCreationException: Error creating bean with name     'hibernatePr
operties': Cannot resolve reference to bean 'dialectDetector' while     setting bean
 property 'properties' with key [hibernate.dialect]; nested exception is     org.spr
ingframework.beans.factory.BeanCreationException: Error creating bean     with name
'dialectDetector': Invocation of init method failed; nested exception is     org.spr
ingframework.jdbc.support.MetaDataAccessException: Error while     extracting Databa
seMetaData; nested exception is java.sql.SQLException:     Driver:org.h2.Driver@317f
67a9 returned null for URL:jdbc:mysql//localhost:3306/tekdays
Message: Error creating bean with name     'transactionManagerPostProcessor': Initia
lization of bean failed; nested exception is     org.springframework.beans.factory.B
eanCreationException: Error creating bean with name    'transactionManager': Cannot
 resolve reference to bean 'sessionFactory' while setting bean property     'session
Factory'; nested exception is     org.springframework.beans.factory.BeanCreationExce
ption: Error creating bean with name 'sessionFactory': Cannot resolve     reference
to bean 'hibernateProperties' while setting bean property     'hibernateProperties';
 nested exception is     org.springframework.beans.factory.BeanCreationException: Er
ror creating bean with name 'hibernateProperties': Cannot resolve     reference to b
ean 'dialectDetector' while setting bean property 'properties' with key     [hiberna
te.dialect]; nested exception is     org.springframework.beans.factory.BeanCreationE
xception: Error creating bean with name 'dialectDetector': Invocation of     init me
thod failed; nested exception is     org.springframework.jdbc.support.MetaDataAccess
Exception: Error while extracting DatabaseMetaData; nested exception is     java.sql
.SQLException: Driver:org.h2.Driver@317f67a9 returned null for     URL:jdbc:mysql//l
ocalhost:3306/tekdays
    Line | Method
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread       Caused by BeanCreationException: Error creating bean with name 'transactionManag
er': Cannot resolve reference to bean 'sessionFactory' while setting     bean proper
ty 'sessionFactory'; nested exception is     org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot     resolve
 reference to bean 'hibernateProperties' while setting bean property     'hibernateP
roperties'; nested exception is         org.springframework.beans.factory.BeanCreationEx
ception: Error creating bean with name 'hibernateProperties': Cannot     resolve ref
erence to bean 'dialectDetector' while setting bean property    'properties' with k
ey [hibernate.dialect]; nested exception is         org.springframework.beans.factory.Be
anCreationException: Error creating bean with name 'dialectDetector':     Invocation
 of init method failed; nested exception is     org.springframework.jdbc.support.Met
aDataAccessException: Error while extracting DatabaseMetaData; nested     exception
is java.sql.SQLException: Driver:org.h2.Driver@317f67a9 returned null     for URL:jd
bc:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by BeanCreationException: Error creating bean with name     'sessionFactory':
 Cannot resolve reference to bean 'hibernateProperties' while setting     bean prope
rty 'hibernateProperties'; nested exception is     org.springframework.beans.factory
.BeanCreationException: Error creating bean with name     'hibernateProperties': Can
not resolve reference to bean 'dialectDetector' while setting bean     property 'pro
perties' with key [hibernate.dialect]; nested exception is     org.springframework.b
eans.factory.BeanCreationException: Error creating bean with name     'dialectDetect
or': Invocation of init method failed; nested exception is     org.springframework.j
dbc.support.MetaDataAccessException: Error while extracting     DatabaseMetaData; ne
sted exception is java.sql.SQLException: Driver:org.h2.Driver@317f67a9     returned
null for URL:jdbc:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by BeanCreationException: Error creating bean with name        'hibernatePropert
ies': Cannot resolve reference to bean 'dialectDetector' while setting     bean prop
erty 'properties' with key [hibernate.dialect]; nested exception is     org.springfr
amework.beans.factory.BeanCreationException: Error creating bean with     name 'dial
ectDetector': Invocation of init method failed; nested exception is     org.springfr
amework.jdbc.support.MetaDataAccessException: Error while extracting     DatabaseMet
aData; nested exception is java.sql.SQLException:     Driver:org.h2.Driver@317f67a9
returned null for URL:jdbc:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by BeanCreationException: Error creating bean with name     'dialectDetector'
: Invocation of init method failed; nested exception is    org.springframework.jdbc
.support.MetaDataAccessException: Error while extracting     DatabaseMetaData; neste
d exception is java.sql.SQLException: Driver:org.h2.Driver@317f67a9     returned nul
l for URL:jdbc:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by MetaDataAccessException: Error while extracting     DatabaseMetaData; nest
ed exception is java.sql.SQLException: Driver:org.h2.Driver@317f67a9     returned nu
ll for URL:jdbc:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by SQLException: Driver:org.h2.Driver@317f67a9 returned null for     URL:jdbc
:mysql//localhost:3306/tekdays
->>  266 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|   1142 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    617 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
| Error Forked Grails VM exited with error

If there is any other code needed, I will provide it.

Best Solution

Hey folks I have figured out the cause of my problem.

  1. First I need to change the driverClassName from "org.h2.Driver" to "com.mysql.jdbc.Driver"
  2. I need to specify the correct database user and password, for development you can use root user.
  3. Insert the missing colon in the url = "jdbc:mysql//localhost:3306/tekdays". The correct one should look like this url = "jdbc:mysql://localhost:3306/tekdays"
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