Pool of VIPs on LTM?

Hi Roman,

 

 

You can't have a VS as a pool member. But you could add more actual servers to a single pool, use an iRule to select among multiple pools or use an iRule to select among multiple virtuals (using the virtual command).

 

 

Overall what are you trying to accomplish or fix?

 

 

Aaron

Hi Aaron,

 

 

Here's what I have: an iRule which redirects traffic to either default or login pool based on the uri. If no members are available in the selected pool, an error page is displayed (not good since second DC might still be available).

 

 

Here's what I want to have: somehow detect (maybe it should be done on GTM layer) that both pools are down, and send traffic to another Data Center. I thought of having one pool per VIP, and have a VIP as a pool member. This way, if no members are active, the VIP should be marked down before it's requested, and LTM or GTM would route traffic to another VIP in second DC. If second DC has the same condition (nothing available), then an error page should be displayed.

 

 

I hope that makes sense.

 

 

Thank you,

 

Roman

Hi Roman,

 

 

Couldn't you use an HTTP monitor on GTM and have an iRule on the LTM virtual server which sends a reset (or HTTP response which the GTM would consider a failure) back if both the login and default pools are down?

 

 

Aaron

Hi Aaron,

 

 

We do have a GTM monitor, but it still happens (maybe due to latency) we forward traffic to LTM with no available pool members. Will sending a "reset command" from one LTM to GTM be enough to take that LTM out of mix and forward to another LTM? Won't I have a racing condition going from LTM to LTM?

 

 

Also, in case nothing is available in both DC, I still want to display error message. Maybe, I need to pass some header var ("LTM failed") from failed LTM? This way, if I receive it and no members are available, I then display an error message?

 

 

Thank you,

 

Roman

Yes,It will make sense.By using TCP half open(Service check monitoring) we can able to check any pool member is active still there in the pool.