Can't start mysqld/mysql - opensuse

Question

first I have to say I'm a mysql newbie.
Basically mysql does not start and says:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysql.sock' (2)
Now Here are the steps with which I ruined everything:
Due to it was not possible to log into my system (otrs) I thought a restore of an older backup would help.
While the restore process the backup manager said I need to drop the old db. I tried it but the process did not finish and so I cancelled it.
After this I tried to reboot the system but had huge problems with this but when I finished the reboot I tried to run mysql but it said it could not find the mysql.socket.
At this point I thought it would be better to reinstall mysql and did so but this did not help.
When trying to start mysqld as mysql user it said:
[ERROR] Found 1 prepared transactions! It means that mysqld was not shut down properly last time and critical recovery information (last binlog or tc.log file) was manually deleted after a crash. You have to start mysqld with --tc-heuristic-recover switch to commit or rollback pending transactions.
trying both did not help:
mysql:/root> /usr/sbin/mysqld --tc-heuristic-recover commit
131213 16:46:00 InnoDB: The InnoDB memory heap is disabled
131213 16:46:00 InnoDB: Mutexes and rw_locks use GCC atomic builtins
131213 16:46:00 InnoDB: Compressed tables use zlib 1.2.7
131213 16:46:00 InnoDB: Using Linux native AIO
131213 16:46:00 InnoDB: Initializing buffer pool, size = 128.0M
131213 16:46:00 InnoDB: Completed initialization of buffer pool
131213 16:46:00 InnoDB: highest supported file format is Barracuda.
131213 16:46:01 InnoDB: Waiting for the background threads to start
131213 16:46:02 Percona XtraDB (http://www.percona.com) 5.5.33-MariaDB-31.1 started; log sequence number 3710898915
131213 16:46:02 [Note] Server socket created on IP: '0.0.0.0'.
131213 16:46:02 [ERROR] Event Scheduler: Failed to open table mysql.event
131213 16:46:02 [ERROR] Event Scheduler: Error while loading from disk.
131213 16:46:02 [Note] Event Scheduler: Purging the queue. 0 events
131213 16:46:02 [ERROR] Aborting
131213 16:46:02 InnoDB: Starting shutdown...
131213 16:46:03 InnoDB: Shutdown completed; log sequence number 3710898915
131213 16:46:03 [Note] /usr/sbin/mysqld: Shutdown complete
Running systemctl start mysql.service fails anytime:
mysql.service - LSB: Start the MySQL database server
Loaded: loaded (/etc/init.d/mysql)
Active: failed (Result: timeout) since Fri, 13 Dec 2013 16:27:12 +0100; 23min ago
Process: 8845 ExecStart=/etc/init.d/mysql start (code=killed, signal=TERM)
CGroup: name=systemd:/system/mysql.service
Dec 13 16:31:21 mysql[8845]: otrs.user_preferences OK
Dec 13 16:31:21 mysql[8845]: otrs.users OK
Dec 13 16:31:21 mysql[8845]: otrs.valid OK
Dec 13 16:31:21 mysql[8845]: otrs.virtual_fs OK
Dec 13 16:31:21 mysql[8845]: otrs.virtual_fs_db OK
Dec 13 16:31:21 mysql[8845]: otrs.virtual_fs_preferences OK
Dec 13 16:31:21 mysql[8845]: otrs.web_upload_cache OK
Dec 13 16:31:21 mysql[8845]: otrs.xml_storage OK
Dec 13 16:31:21 mysql[8845]: performance_schema
Dec 13 16:31:21 mysql[8845]: Phase 3/3: Running 'mysql_fix_privilege_tables'...
I have absolutely no clue what to do. Could anyone help me?
How can the otrs tables been droped/deleted without using the mysql DROP command?
Would this help anyway?
Thank you.

Answer 1

mysqld --tc-heuristic-recover=ROLLBACK
Didn't quite do the magic for me. However the following worked
mysqld_safe --tc-heuristic-recover=COMMIT

Answer 2

I was able to overcome this issue on CentOS 6 with
service mysql start --tc-heuristic-recover=ROLLBACK
which ultimately discarded the commit in question. I'm not sure if systemd scripts support passing additional parameters. Maybe you could try and run it manually with the =
mysqld --tc-heuristic-recover=ROLLBACK

Answer 3

On mysql 5.6.x, and because of this off-by-one https://bugs.mysql.com/bug.php?id=70860 bug, I was able to get past this by doing
sudo service mysql start --tc-heuristic-recover=0
which presumably commits the tx.

Answer 4

Answer from ->> https://www.youtube.com/watch?v=qr-t8ksYO78
go to my.cnf file, note that you will find multiple my.cnf file, i had to look at all of them to find this->
# The MySQL server
[mysqld]
user = mysql
port=3306
socket = /opt/lampp/var/mysql/mysql.sock
Copy the socket path and writ it like ->
mysql -u root -p --socket=/opt/lampp/var/mysql/mysql.sock
Thanks

Answer 5

If any of the above doesn't work for you.
Edit mysql config file by doing the below:
sudo nano /etc/mysql/my.cnf and add tc-heuristic-recover=rollback under [mysqld]
Try to start mysql/mariadb server by
sudo systemctl start mysqld.service and it should fail with this error Can't init tc log.
Don't worry, just edit the config file again and comment tc-heuristic-recover=rollback
Try to start the mysql server again with sudo systemctl start mysqld.service and it should work fine.
Check the status to confirm systemctl status mysqld.service

Answer 6

You can try this command that I use Centos 7 that is work:
#mysqld_safe --wsrep-recover --tc-heuristic-recover=ROLLBACK
and then restart a service again.