Monitoring ephemeral pool members & nodes
Hi, I'm looking to use the dynamic FQDN resolution for nodes / pool members, but have a few queries... If an Ephemeral pool member goes down, does that failure trigger anything on the DNS / Node side? Immediate resolution in case the result has changed etc.? Resolution appears to be wholly at the node level, suggesting the health of the pool member is irrelevant, and always limited to the IP's returned periodically by the DNS lookup attached to the node - and "DNS monitoring" merely means a resolution occured. The documentation about "auto populate" is confusing me. What is the real life difference between Enabled and Disabled? I see that when Disabled, the very first result is always used, however it still creates the Ephemeral node, it's still done periodically etc., so the only meaningful difference seems to be if more than one A is returned at a time. There's reference to Enabled removing members that are no longer being returned, but isn't that already implicitly true for Disabled? If that one result changes, then the pool member will change accordingly. Is it really any more meaningful than "Disabled = ignore additional results, Enabled = create nodes for all answers."? What would it mean for a node to auto populate, but a pool member using that node to NOT be set to do that? I see we only get a single pool member, but multiple nodes... but what is the consequence of this? Is there a reason this would be found useful? How does the node resolution internal work with the DNS Cache option in the system settings? The reoslution does use these settings, right? Would it make sense to set the resolution low ~ 5 seconds and enable caching on LTM, meaning that the name would be resolved almost as soon as the TTL expires on the record, thereby falling out of the cache? Could this be seen as a realistic best practise, or are there dragons hiding around here? Setting node resolution at an arbitrary hour interval as per default seems very dangerous to me. Thanks!