Forum Discussion

Nimbostratus

Jun 26, 2014

Solved

LTM - Load Balancing iRule

We have a VIP that takes two connections per day coming from the same client. The client opens the two connections within the same second of each other, each connection stays open for 30 seconds. P...

nitass_89166
Jun 29, 2014
The intermittent issue is that sometimes the two connections get load balanced to one member and sometimes each member receives one connection. Is there an iRule I can put in place to ensure one connection goes to each member every time?

what you are seeing is due to how cmp works. i think disabling cmp should work.

sol14358: Overview of Clustered Multiprocessing (11.3.0 and later)

http://support.f5.com/kb/en-us/solutions/public/14000/300/sol14358.html

if you do not want to disable cmp, irule similar to Matt's suggestion is needed (global variable will demote cmp, so you have to store global_myvsconncnt in session table instead).

sol13033: Constructing CMP-compatible iRules

http://support.f5.com/kb/en-us/solutions/public/13000/000/sol13033.html

Dave_21103

Nimbostratus

Jun 27, 2014

Matt, Thanks for the suggested iRule. The developers want me to attempt an iRule and I'm willing to try the one you provided. I will mark the answer as correct if it works for us. Also Patrick, I will try your suggestion as well if Matt's doesn't work. At this point, I'm not too concerned if a solution disables CMP as this VIP only takes 4 connection request per day at the most.

Matt_Breedlove_
Nimbostratus
Jun 27, 2014
Great Dave, hope it works out for you. It sounds like you have ruled out any other possible source client from using that vip including monitoring Couple things to note, the forums converted the literal greater than character to a > in the irule, so you will want to change that when copy/pasting. Also if your pools are not using port 80 for the members in the pool that will need to be changed as well on the line with the member IP addresses
Dave_21103
Nimbostratus
Jun 30, 2014
I did rule out any other possible source clients from using the VIP. Thanks for the note about greater than symbol Matt! Very much appreciate all of your help. I'm planning to deploy the iRule into Production environment next week and will let you know how things went.
Dave_21103
Nimbostratus
Jun 30, 2014
Matt does the iRule disable CMP for the entire LTM or just the VIP it is applied to?
Cory_50405
Noctilucent
Jun 30, 2014
Just the VIP it's applied to.