MySQL grant use?

[Alex Dean]

On Jul 26, 2010, at 2:03 AM, der.hans wrote:

> Am 25. Jul, 2010 schwätzte Technomage so:
>
>> There is a program in OpenBSd that can help with this. its called  
>> carp. you have 2 machines running, one the primary and the other  
>> the backup. if the main fails, carp kicks in and take possession if  
>> the relevant ip addresses (as far as your network is concerned, you  
>> never lost connectivity). I am not sure of they have a similar  
>> command in linux, but its worth checking on. this in combination  
>> with a live running backup of mysql would mean that you don't have  
>> to worry about manually changing ip's on the other box, it would be  
>> done automatically.
>
> There are a couple of such tools for GNU/Linux. Carp is one of  
> them :).
>
> Not quite what we're talking about at this point :).
>
> Live failover is something else we need to add to the  
> infrastructure. That
> task will take some effort to get approved.
>
> For now, I just need to get our base setup in order and make sure I  
> have
> all backups and monitoring working.
>
> I should be playing with carp and other such tools at home.
>

If I understand it correctly, carp will get your IPs to failover, but  
that's only part of the problem.  In this case you'd also have to  
promote the slave, and demote the master.  I think something like  
heartbeat or pacemaker might do the job more completely, since they  
can manage many more kinds of resources rather than just IPs.  Running  
mysql on drbd, and using heartbeat or pacemaker for cluster  
management, is a solid option as well.