Sorry your request was taken in the wrong way, I get this request for various things all the time and they are serious about it. I also see on a regular basis people get two T1 connections from the same loop provider, to the same ISP and call it redundant. So the question remains, how many 9's do you need?
I'd look at having two servers, one a master and another a slave, and some software that can tell when one of them goes down then promote the salave to master, and take over the IP address of the down system.
-- Michael Conlen
Rick Franchuk wrote:
On Thu, 19 Jun 2003, Michael Conlen wrote:
First get an acceptable outtage rate. Your only going to get so many nines, and your budget depends on how many. The system will fail at some point, no matter what, even if it's only for a few seconds. That's reality. Figure out what kinds of failures you can tolerate based on how many 9's you get and what kinds you have to design around. From there you can figure out a budget. 99.999% uptime is 5 minutes and 15 seconds per year of total downtime. 99.99% is 52.56 minutes and so on. At some point something will happen, and I've never seen anyone offer more than 5 9's, and IBM charges a lot for that. Then, figure out everything that could cause an outtage, figure out how to work around them and give them a budget. Watch how many 9's come off that requirement.
Obviously my hyperbolic emphasis on uptime has brought out the pedant in some. I'm not expecting unrealistic results... I would have thought my 'breathless' expression of uptime requirement would be seen as a bit of exaggeration. I'll try to be more explicit in the future.
If you have to use MySQL I'd ditch PC hardware and go with some nice Sun kit if you haven't already, or maybe a IBM mainframe.
The code using mysql represents several thousand man hours of work, and although the database-using elements are somewhat abstracted there's guaranteedly mysql linguistic variants spread all throughout the code. It'd be substantial work converting... not impossible, but a pricey PITA. A mysql solution would be preferable under the circumstances.
<hand waving extreme commentary about the impossibilty of the situation and general hyperbole snipped>
There's a lot of issues to consider in there, and you probably want someone
with a graduate degree in computer science to look over the design for you.
(anything this critical and I get someone smarter than me to double check my
designs and implementations).
I'm sure more than one of the various graduates on our design team will do so, seeing how their code will likely need to be modified somewhat to take advantage of the new setup.
On the other hand, if you have all this money, look at some of the <etc and so on>
This is just a quick run down of immediate issues in a 24x7x365, it's not exhaustive. Think about every cable, every cord, every component, from a processor to a memory chip and think about what happens when you pull it out or unplug it, then make it redundant.
Yes, we're quite aware of what 'redundancy' means. Thank you ever so much for pointing out the painfully obvious, much of which has already been taken care of inside the time, engineering and money constraints given us.
Now, if you have some actual HELP to give regarding the viability of MySQL to the application of the problem at hand...
-- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
