From what I can see in the mysql log files your database seams to be corrupt since 09.01.15. Possibly because you updated that package. See here:
[CODE]…
150109 12:29:46 InnoDB: 5.5.40 started; log sequence number 1720871
…
150109 12:29:46 InnoDB: Starting shutdown…
150109 12:29:47 InnoDB: Shutdown completed; log sequence number 1720871
150109 12:29:47 [Note]
150109 12:29:47 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
150109 14:30:12 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
…
2015-01-09 14:30:14 9509 [Note] InnoDB: Waiting for purge to start
2015-01-09 14:30:14 9509 [Note] InnoDB: 5.6.22 started; log sequence number 1725017[/CODE]
See the different version numbers… After that you have lots and lots of errors in your log file!!
[CODE]…
2015-02-09 15:19:23 14629 [ERROR] Native table ‘performance_schema’.‘users’ has the wrong structure
2015-02-09 15:19:23 14629 [ERROR] Native table ‘performance_schema’.‘accounts’ has the wrong structure
2015-02-09 15:19:23 14629 [ERROR] Native table ‘performance_schema’.‘hosts’ has the wrong structure
…
2015-02-09 15:27:08 a469db70 InnoDB: Error: Table “mysql”.“innodb_table_stats” not found.
2015-02-09 15:27:08 a469db70 InnoDB: Error: Fetch of persistent statistics requested for table “fog”.“images” but the required system tables mysql.innodb_table_stats and mysql.innodb_index_stats are not present or have unexpected structure. Using transient stats instead.
…[/CODE]
Searching the web for this error messages you find a lot of people having kind of similar issues with mysql!!
See here: [url]http://dba.stackexchange.com/questions/48166/cannot-open-table-mysql-innodb-index-stats[/url]
Possibly a solution: [url]http://forums.mysql.com/read.php?22,578559,579891[/url]