Solve two basic problems of MySQL service in Linux _ MySQL

Basically, mysql has two major problems. 1. there is no problem starting mysql for the first time. I have done some operations on mysql, especially when I delete some accounts that are not in mysql, I will encounter this problem when I restart mysql # etcinit. dmysqldrestartstoppi basically encounters two major problems when using mysql.

1. there is no problem starting mysql for the first time. after you perform some operations on mysql, especially after deleting some accounts in mysql, you will encounter such problems when you restart mysql.

#/Etc/init. d/mysqld restart Stopping mysql [OK] Timeout error occurred trying to start MySQL Daemon. [failure]

However, mysql has actually started at this time, because the netstat-ln command is used to check that Port 3306 has been started. mysql-u root-p password can also be used to connect to the database.

This is actually a bug in the mysql-3.x (you can look at the bugzilla of mysql and the bugzilla of redhat ).

What causes connection timeout?

Let's take a look at how the/etc/init. d/mysqld startup script works. pay attention to the following section.

# If you 've removed anonymous users, this line must be changed # Use a user that is allowed to ping mysqld. Ping = "/usr/bin/mysqladmin-uUNKNOWN_MYSQL_USER ping" # Spin for a maximum of ten seconds waiting for the server to come up If [$ ret-eq 0]; then For x in 1 2 3 4 5 6 7 8 9 10; do If [-n "'$ ping 2>/dev/null"']; then Break; Else Sleep 1; Fi Done If! ([-N "'$ ping 2>/dev/null"']); then Echo "Timeout error occurred trying to start MySQL Daemon. "action $" Starting $ prog: "/bin/false Else Action $ "Starting $ prog:"/bin/true Fi Else Action $ "Starting $ prog:"/bin/false Fi [$ Ret-eq 0] & touch/var/lock/subsys/mysqld Return $ ret

We can see that the script determines whether mysql is started and uses the mysqladmin ping command.

To execute this command correctly, you must be able to log on to mysql. now some default accounts have been deleted, and other accounts have set a password (no password is set by default ). so it cannot connect to mysql.

Run the following command to test

# Mysqladmin-u root-ppassword ping Mysql alive

When you provide the account and password, the ping command can be correctly executed.

This bug can be solved in mysql's new mysql4.x.

However, RH9 to FC3 has been using mysql3.x (however, mysql officially seems to have launched mysql4.1, FC needs to consider the problem ).

So I used the following method for temporary solution.

A) create an account without a password or any permissions.
B) modify/etc/init. d/mysqld

The following are my specific operations:

# Mysql-u root-p passwd Mysql> GRANT select ON test. *Daemon @ localhost Mysql> revoke select on test. * fromDaemon @ localhost

Open/etc/init. d/mysqld

Set the following line

Ping = "/usr/bin/mysqladmin-uUNKNOWN_MYSQL_USER ping"

Change

Ping = "/usr/bin/mysqladmin-udaemon ping"

Save and exit.