SQLSTATE[08004] [1040] Too many connections

#0 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Zend/Db/Adapter/Pdo/Mysql.php(96): Zend_Db_Adapter_Pdo_Abstract->_connect()
#1 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Varien/Db/Adapter/Pdo/Mysql.php(300): Zend_Db_Adapter_Pdo_Mysql->_connect()
#2 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Zend/Db/Adapter/Abstract.php(858): Varien_Db_Adapter_Pdo_Mysql->_connect()
#3 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Zend/Db/Adapter/Abstract.php(928): Zend_Db_Adapter_Abstract->quote('aitsys_setup', NULL)
#4 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Varien/Db/Adapter/Pdo/Mysql.php(1397): Zend_Db_Adapter_Abstract->quoteInto('code =?', 'aitsys_setup', NULL, NULL)
#5 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Zend/Db/Select.php(1000): Varien_Db_Adapter_Pdo_Mysql->quoteInto('code =?', 'aitsys_setup', NULL)
#6 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Zend/Db/Select.php(475): Zend_Db_Select->_where('code =?', 'aitsys_setup', NULL, true)
#7 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/lib/Varien/Db/Select.php(123): Zend_Db_Select->where('code =?', 'aitsys_setup', NULL)
#8 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Model/Database.php(122): Varien_Db_Select->where('code =?', 'aitsys_setup')
#9 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Model/Platform.php(374): Aitoc_Aitsys_Model_Database->dbVersion()
#10 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Model/Platform.php(368): Aitoc_Aitsys_Model_Platform->_checkNeedCacheCleared()
#11 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Model/Platform.php(31): Aitoc_Aitsys_Model_Platform->init()
#12 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Abstract/Service.php(130): Aitoc_Aitsys_Model_Platform::getInstance()
#13 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Abstract/Service.php(411): Aitoc_Aitsys_Abstract_Service->platform()
#14 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Abstract/Service.php(444): Aitoc_Aitsys_Abstract_Service::_initSource('/var/www/aerost...', 'Aitoc_Aitchecko...')
#15 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitcheckoutfields/Model/Customer/Account/Observer.php(11): Aitoc_Aitsys_Abstract_Service::initSource('/var/www/aerost...', 'Aitoc_Aitchecko...')
#16 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/local/Aitoc/Aitsys/Model/Rewriter/Autoload.php(155): include('/var/www/aerost...')
#17 [internal function]: Aitoc_Aitsys_Model_Rewriter_Autoload->autoload('Aitoc_Aitchecko...')
#18 [internal function]: spl_autoload_call('Aitoc_Aitchecko...')
#19 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Model/Config.php(1348): class_exists('Aitoc_Aitchecko...')
#20 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/Mage.php(432): Mage_Core_Model_Config->getModelInstance('aitcheckoutfiel...', Array)
#21 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Model/App.php(1277): Mage::getModel('aitcheckoutfiel...')
#22 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/Mage.php(416): Mage_Core_Model_App->dispatchEvent('controller_fron...', Array)
#23 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Controller/Varien/Front.php(147): Mage::dispatchEvent('controller_fron...', Array)
#24 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Model/App.php(743): Mage_Core_Controller_Varien_Front->init()
#25 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Model/App.php(1086): Mage_Core_Model_App->_initFrontController()
#26 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/code/core/Mage/Core/Model/App.php(349): Mage_Core_Model_App->getFrontController()
#27 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/app/Mage.php(640): Mage_Core_Model_App->run(Array)
#28 /var/www/aerostich/aerostich.com/magento-1.6.2.0-git/index.php(80): Mage::run('', 'store')
#29 {main}