Why I am seeing"System Unresolved DNS" that is appearing in the directory Backends of each Agent in the Investigator?
CA APM 10.x
There are a few reasons this could be happening:
1. It could be the application is calling some backend on an IP address which is not being resolved by DNS on the Agent machine.
2. Or if the specific IP's belong to a DMZ Network, they will not be resolved by the DNS on the system where the Agent is installed.
3. Or if the host name where the Agent is installed is not obtained within the time frame, check the IntroscopeEnterpriseManager.log to see if it contains the below "warning" message:
[WARN] [IntroscopeAgent.DnsServiceExecutor] Failed to obtain host name in 200 ms. Consider changing property introscope.agent.dns.lookup.max.wait.in.milliseconds
On the IntrsocopeAgent.profile, try updating the below property to a higher value, for example 1000. You must restart the managed application for this property change to take effect.
introscope.agent.dns.lookup.max.wait.in.milliseconds=1000
4. Look for any possible DNS issues within the environment.