No persistence to pool members

Once again Thanks Hannes for your tips and actions. based on our investigation there was no evidence show that node down or up, but answer to your qn, BIG-IP delete the persistence records i think.

currently one member in test2 pool disabled for interim resolution. I will consider and bring up to the next level for changing the pool configuration/cookie based persistence as well as irule enhancement and will update about the issue. But it will take up some time since we don't have test envt. to simulate and fix.