LB_SELECTED Pool: _tmm_firepass_apd_pool

Hi, I have put lots of log statement in my irules for debugging purposes. And I see something strange for section LB_SELECTED. I am using an APM policy with my VS and this is happen before ACCESS_POLICY_COMPLETED. In the irule I have HTTP_REQUEST and ACCESS::enabled for this specific path. Then I can see for LB_SELECTED the following: Status: up Server: 127.0.0.1 Pool: _tmm_firepass_apd_pool

Later when comming to ACL_ALLOWED the correctly server and pool are selected.

So what is _tmm_firepass_apd_pool?

Regards, Erik