Cant get general log to show queries in mysql - mysql

Question

Not sure what's going on here, as far as I know everything is set as it's supposed to be but the log stays empty:
[root#myLaptop Me]# cat /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
[mysqld_safe]
log-error=/var/log/mysqld.log
log=/var/log/mysqld.general.log
general_log_file=/var/log/mysqld.general.log
pid-file=/var/run/mysqld/mysqld.pid
[root#myLaptop Me]# service mysqld stop
Redirecting to /bin/systemctl stop mysqld.service
[root#myLaptop Me]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service
[root#myLaptop Me]# mysql -u root -p
Enter password:
... Welcome stuff
Server version: 5.5.30 MySQL Community Server (GPL)
mysql> SET GLOBAL log_output = "FILE";SET GLOBAL general_log = 'ON';
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.05 sec)
mysql> SHOW PROCESSLIST;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+-----------+------+---------+------+-------+------------------+
| 3 | root | localhost | NULL | Query | 0 | NULL | SHOW PROCESSLIST |
+----+------+-----------+------+---------+------+-------+------------------+
1 row in set (0.00 sec)
mysql> quit
Bye
[root#myLaptop Me]# tail /var/log/mysqld.general.log
[root#myLaptop Me]# <= shows nothing at all
[root#myLaptop Me]# ls -l /var/log/mysqld.general.log
-rw-r--r--. 1 mysql mysql 0 May 31 10:06 /var/log/mysqld.general.log
[root#myLaptop Me]# tail /var/log/mysqld.log
130531 10:28:04 InnoDB: Completed initialization of buffer pool
130531 10:28:04 InnoDB: highest supported file format is Barracuda.
130531 10:28:04 InnoDB: Waiting for the background threads to start
130531 10:28:05 InnoDB: 5.5.30 started; log sequence number 2969208
130531 10:28:05 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
130531 10:28:05 [Note] - '0.0.0.0' resolves to '0.0.0.0';
130531 10:28:05 [Note] Server socket created on IP: '0.0.0.0'.
130531 10:28:05 [Note] Event Scheduler: Loaded 0 events
130531 10:28:05 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.30' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL)
[update]
I think fedora 17 starts mysql with parameters that override the my.cnf the log is not where the my.cnf tells it to be:
[root#Laptop Symfony]# mysql -u root -p
mysql> select ##global.general_log_file;
+----------------------------+
| ##global.general_log_file |
+----------------------------+
| /var/lib/mysql/Laptop.log |
+----------------------------+

Answer 1

First, I would check the logging options
please see the logging options from IBM MySQL reference
On my servers, I always create a new directory in /var/log and "give" it to mysql (to be executed as root or via sudo)
sudo mkdir /var/log/mysql
sudo chown mysql:mysql /var/log/mysql
then all logging options from my.cnf are a file inside that directory
log=/var/log/mysql/general.log
log-error=/var/log/mysql/error.log
log-slow-queries=/var/log/mysql/slowquery.log
to be sure in any case, mysql can create and access the files. Moreover, it helps to visit all the mysql log files at once, since the /var/log directory is pretty busy with many things not related to mysql.
Then, as why the current log files are empty, some log information may be buffered at the time you check the files. To force mysql to write to the files (or the underlying IO libraries) so that the text is visible from outside mysql (ie tail), you can execute (mysql command)
FLUSH LOGS;
There is an interesting article on empty log files.

Answer 2

be sure that variable:general_log=ON，if this variable is "OFF"，mysql will not print anything to general_log file.
you can check mysql error log file to look up is there any errors happened