Site gone offline after aborted mysql restart After trying new my.cnf, restarting  mysql took to long (apparently due to some incompatible commands in the experimental config) , so I restored to my original my.cnf and restarts mysql successfully. But now I see that the site has gone off line. I tried the 'desparate' solution, i.e. issued:

UPDATE variable SET value = 's:1:"0";' WHERE name= 'site_offline';
DELETE FROM cache WHERE cid = 'variables';


but had no effect. Then I changed my database admin credentials. then, to possibly counter a corrupted table, I tried to repaire the database (MyISAM enginge) using 

mysqlcheck -uroot -pPASS --auto-repair --optimize --databases MYDB 


I also rebuilt the file permissions on the server.

No cure either. 

I'd seen before that the site went offline on whim, but now this seems to become persistent. really appreciate your help to overcome this nasty problem.
It sounds like your database is broken. Drupal can't work without a database, and will display site offline if it can't connect to the database. If you fix your database, (And the data is still intact) Drupal should work fine.

For questions about databases you should go to dba.stackexchange.com