Upgrade MySQL server

I recently had to upgrade a mysql server from version 4.0.x to 5.0.x and ran into the following issues.

#1 Error Client does not support authentication protocol

This was due to the fact that the mysql client was older than 4.1 and the server was upgraded to 5.0.x and according to the MySQL documentation: MySQL 5.0 uses an authentication protocol based on a password hashing algorithm that is incompatible with that used by older (pre-4.1) clients.

You can either upgrade the mysql client to a version 4.1 or greater or run the following for the user name that needs to connect with a mysql client version of 4.0 or less.

mysql> SET PASSWORD FOR
    -> 'some_user'@'some_host' = OLD_PASSWORD('newpwd');


In addition, you may need to edit your mysql server 
to accept old password. You can do this in the /etc/my.cnf 
file by adding old-password = 1 to the [mysqld] section and
restarting mysql.

#2 DNS issues. I was getting an error that the username couldn't
connect from a particular hostname.  To take DNS queries out of the
connection, you can add skip-name-resolution to the [mysqld] section
of your /etc/my.cnf file and this will tell mysql server daemon to 
not perform a DNS lookup of the calling IP address. Restart mysql.

Change hostname OS X

Panther

#1 Edit System Preferences -> Sharing and change the computer name.

#2 Edit /etc/hostconfig  and change the hostname variable.

#3 Reboot

Leopard

#1 System Preferences -> Sharing and change the computer name

#2 Edit /Library/Preferences/SystemConfiguration/preferences.plist and change the hostname variable in that file

#3 Reboot

mcelog warning bytes ignored consider update

I started getting these hourly warning messages after taking about a week off for vacation.

mcelog: warning: 18446744073709551600 bytes ignored in each record
mcelog: consider an update
mcelog: warning: 18446744073709551600 bytes ignored in each recordmcelog: consider an update

I emailed a RedHat users list and a member suggested the following:

That actually sounds like data structures for the mce record have changed size (increased) and the userspace mcelog daemon doesn’t know about the extra info. Did you upgrade your kernel?

I have kernel* excluded in my yum.conf file so it looks like mcelog was updated and the kernel package wasn’t. I upgraded the kernel and rebooted and that fixed the issue. Now to do some investigating on mce records and data structures.

So from the following post: https://bugzilla.redhat.com/show_bug.cgi?id=507026 it looks like the kernel’s /usr/include/asm/mce.h ‘struct mce’ definition does not match the mcelog/mcelog.h ‘struct mce’ definition which is what was causing the error message.  (Ie. you need to make sure there isn’t an upgrade for your kernel package if there is an update for the mcelog package).