Ubuntu 10.04 - upgrade to MYSQL causing " Can't connect to local MySQL server"

[Alex_B]

Hello

Ive had Zabbix 1.8.1 running on Ubuntu 10.04 for some time now and has been working great. I've just applied some recent updates (which included mysql updates.. and stupidly I did not run snapshot of the server (or recent backup) beforehand).. Ever since I cannot gain access to Zabbix due to mysql connect errors:

mysql_connect(): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)[/usr/share/zabbix/include/db.inc.php:58]

This points to mysql not running but it is running and I can confirm processing information.

when I restart the mysql service I can initially connect the one time using commandline mysql.. but trying again gives similar error to above on the commandline:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)

Ive recearched the error and possibly looking to permission errors but im not sure where. Ive adjusted the mysql config file but to no avail. mysql looks to be there and appears to be working it appears to be some communication from the local console.

If anyone has any pointers that would be great..

[justinc]

anything interesting in:
/var/lib/mysql/<hostname>.err

[Alex_B]

Actually nothing in there - probably need to turn my loging up. All errors appear to be here /var/log/mysql/error.log

Turn out I have fixed the issue.
check out this link. http://www.softwareprojects.com/reso...nodb-1634.html

Has a lot of info on recovering Mysql

I had to do number 7.. I could get access to mysql dialog direct after a restart so:

Step 1: Add this line to your /etc/my.cnf configuration file:

[mysqld] 
innodb_force_recovery = 4

Step 2: Restart MySQL. Your database will now start, but with innodb_force_recovery, all INSERTs and UPDATEs will be ignored.

Step 3: Dump all tables

mysqldump --force --compress --triggers --routines --create-options -uUSER -pPASSWORD --all-databases > /home/yourhome/databases.sql


Step 4: Shutdown database and delete the data directory.

i moved folder so:

sudo mv /var/lib/mysql /var/lib/mysql.old

Step 5: Run mysql_install_db to create MySQL default tables

Step 6: reset your root password back or a different one

mysqladmin -u root password NEWPASSWORD

Step 7: restore all databases back.

mysql -u root -p </home/yourhome/databases.sql

This worked well.