Forum Discussion

Teemu_Kunnari_1's avatar
Teemu_Kunnari_1
Icon for Nimbostratus rankNimbostratus
Jan 18, 2016

Directing traffic to a node based on a specific uri only if the node is up

Hi,   A customer is hoping to direct traffic to a /SOMEURI and when request is for that URI traffic should go to a different pool and member than the original ones on the VS. And only to this new ...
application delivery
LTM
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Jan 20, 2016

Hi Teemu,

 

I would like to recommend to not check the available members on each single web request, since this would put some unnecessary overhead to your LTM.

 

The better solution would be to use the "Priority Group" pool feature. In this case you would use two independent pools pointing to the same set of nodes. The pool which would be used for /someuri would then get additional "Priority Group" pool settings.

 

Default Pool

 

  • Member1 = Prio 0

     

  • Member2 = Prio 0

     

  • Member3 = Prio 0

     

  • Member4 = Prio 0

     

  • Member5 = Prio 0 (adding this member is optional)

     

/someuri Pool

 

  • Member1 = Prio 0

     

  • Member2 = Prio 0

     

  • Member3 = Prio 0

     

  • Member4 = Prio 0

     

  • Member5 = Prio 1

     

Now your iRule would just need to switch between the different pools based on the given URI, but without checking the availability at all...

 

For further Priority Groups information: https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-concepts-11-1-0/ltm_pools.html1216212

 

Cheers, Kai