Forum Discussion
johndegern_4568
Nimbostratus
NimbostratusHow many redirects can I have in a single iRule?
I have a project where I would like to use BigIP to redirect 200+ domains to different domains. Sometimes to a host::uri.
How many "If Else" can one have in an iRule? Would a better approach be to have separate iRules for each redirection?
I am very interested in using a best practice approach for this device and definitely don't want to put any major stress to a bustling production system.
Thanks in advance to the guru community.
- The_BhattmanHi John,
if you are looking a 200 domains then my suggestion is to use class command http://devcentral.f5.com/wiki/default.aspx/iRules/class.html
It's flexible enough to use when you large set of redirections.
I hope this helps
Bhattman 
johndegern_4568I probably should have specified the version in my first post. We're using BIG-IP 9.3.1 Build 37.1 and the link you provided is for v10.
Anything else? Is it a big deal to do the redirects using if/elseif/elseif/elseif?
hoolioCirrostratus
You could chain 200 if/elseif.../else together, but it would get a bit unwieldy. You could still use a datagroup in 9.3.1. But you'd use matchclass or findclass to search the class. ~200 lines shouldn't add a lot of overhead but it's always good to do performance testing if you can before using a rule like this in production. If the redirects are all of the same VIP, it would be best to combine the redirects in a single iRule. This helps you avoid attempting to send multiple redirects on the same request (which triggers a runtime TCL error).
For details you can check the various wiki pages:
http://devcentral.f5.com/wiki/default.aspx/iRules/matchclass
http://devcentral.f5.com/wiki/default.aspx/iRules/findclass
http://devcentral.f5.com/wiki/default.aspx/iRules/timing
Aaron- The_BhattmanDon't forget the SWITCH command (http://devcentral.f5.com/wiki/default.aspx/iRules/switch.html)
Bhattman - johndegern_4568Thats what I started using rather than elseif statements. It works great!! Thanks
