[Bitrix\Main\DB\ConnectionException]
Mysql connect error [localhost]: (2006) MySQL server has gone away (400)
/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:65
#0: Bitrix\Main\DB\MysqliConnection->connectInternal()
/home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:122
#1: Bitrix\Main\DB\MysqliConnection->queryInternal(string, NULL, NULL)
/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:330
#2: Bitrix\Main\DB\Connection->query(string, NULL, integer, integer)
/home/bitrix/www/bitrix/modules/main/lib/db/connection.php:358
#3: Bitrix\Main\DB\Connection->queryScalar(string)
/home/bitrix/www/bitrix/modules/security/lib/session.php:110
#4: Bitrix\Security\SessionTable::lock(string, integer)
/home/bitrix/www/bitrix/modules/security/classes/general/session_db.php:52
#5: CSecuritySessionDB::read(string)
#6: session_start()
/home/bitrix/www/bitrix/modules/main/include.php:281
#7: require_once(string)
/home/bitrix/www/bitrix/modules/main/include/prolog_before.php:14
#8: require_once(string)
/home/bitrix/www/bitrix/modules/main/include/prolog.php:10
#9: require_once(string)
/home/bitrix/www/bitrix/header.php:1
#10: require(string)
/home/bitrix/www/catalog/index.php:2
#11: include_once(string)
/home/bitrix/www/bitrix/modules/main/include/urlrewrite.php:159
#12: include_once(string)
/home/bitrix/www/bitrix/urlrewrite.php:2
Fatal error: Uncaught Bitrix\Main\DB\ConnectionException: Mysql connect error [localhost]: (2002) Connection refused in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php:65
Stack trace:
#0 /home/bitrix/www/bitrix/modules/main/lib/db/mysqlcommonconnection.php(130): Bitrix\Main\DB\MysqliConnection->connectInternal()
#1 /home/bitrix/www/bitrix/modules/main/lib/db/connection.php(716): Bitrix\Main\DB\MysqlCommonConnection->getTableFields('b_sec_session')
#2 /home/bitrix/www/bitrix/modules/main/lib/db/sqlhelper.php(387): Bitrix\Main\DB\Connection->getTableField('b_sec_session', 'SESSION_ID')
#3 /home/bitrix/www/bitrix/modules/main/lib/entity/datamanager.php(974): Bitrix\Main\DB\SqlHelper->prepareAssignment('b_sec_session', 'SESSION_ID', 'QS6XRx6lN26714e...')
#4 /home/bitrix/www/bitrix/modules/security/classes/general/session_db.php(92): Bitrix\Main\Entity\DataManager::delete(Array)
#5 [internal function]: CSecuritySessionDB::write('QS6XRx6lN26714e...', '')
#6 [internal function]: session_write_close()
#7 {main}
in /home/bitrix/www/bitrix/modules/main/lib/db/mysqliconnection.php on line 65