Irule Prefernce

Shivesh: there are a couple of other options here that may be worth looking into, but without more information on how you've got your hosting environment set up it's a little hard to say which one is best. In the hopes that something sticks, I'll toss a couple out.

 

 

1) Take advantage of priority grouping. For example, you could have a simple page that you monitor on the web servers, and when the dev team needs to test a new release on a particular set of servers they can simply toggle that page's content - for example, from "Pass" to "Fail" or similar. This will cause the health check to fail and your 'fallback' servers will come online and serve your maintenance page. The drawback to this approach is that you'll have to be very careful to disable the right set of servers (i.e. the systems with the higher priority in the pool). There's also more setup involved with this.

 

 

2) Use iControl to manually disable the systems in question. This is something that your dev team can automate relatively easily and it'll work great. You can manually disable the higher priority systems and let the fallback systems in the priority group serve up the maintenance page. The drawback here is that it may not be granular enough for you to deal with per-host maintenance windows.

 

 

3) Take advantage of the 'fallback host' setting in the HTTP profile, so when you disable the servers you can automatically fall back. The drawback here is that it's a fairly 'global' thing to do, so if you're doing lots of name-based virtual hosts it may not fit every situation.

 

 

4) Use an iRule with a data group that contains a set of hostnames to selectively disable. This will probably get you closest to your 'dynamic' setup, as you can automatically update this list via (you guessed it!) iControl. So for example you could use something like this: http://devcentral.f5.com/Default.aspx?tabid=53&forumid=5&postid=3005&view=topic. While their goals are different in this thread, the technique still applies.

 

 

This last option would be my guess as the most useful one for you.

 

I hope this helps,

 

Matt