GTM sorry server/last resort best practices

Thanks for the reply Anthony.

 

 

The problem is that if using an iRule to implement a "sorry server" service (i.e. if all pool members are down, then use pool sorry server), then the LTM virtual will be marked as in service when all pool members are down as the request is rebalanced to a sorry server.

 

 

It is possible to use an LTM fallback host, but this is undesirable as we would prefer just to serve up a sorry server response rather than issue a redirect (as the fallback host functionality does).

 

 

From a GTM perspective, this means that as long as a sorry server is available, the LTM virtual is still in service. If the LTM is used in a GTM service with the Global Availability LB algorithm, then the service will never fail-over to the next virtual in the pool.

 

 

A possible workaround for this may be to remove the sorry server iRule at a LTM level, then create a GTM sorry server virtual/pool and specify this as the last virtual/pool where GA is used.