Problem:
The CA APM Introscope Agent log shows the following DNS errors:
[ERROR] [IntroscopeAgent.DnsServiceExecutor] get DNS name by IP address null
Environment:
CA APM 10.0, CA APM 10.1
Cause:
Your environment is having DNS issues.
Workaround:
In the agent profile, there is a property to make DNS resolution happen either in a separate thread (default behavior) or in the Application thread (known as "direct" mode):
introscope.agent.dns.lookup.type
When in "direct" mode, the Application thread will block until the DNS query returns or times out. This is not ideal and thus is not the default.
When in "separateThread" mode, the DNS query will be allowed a max wait time of 200ms. This is controlled by the property:
introscope.agent.dns.lookup.max.wait.in.milliseconds
If 200ms is not enough, try increasing this value.
Notes:
1. An agent restart is required.
2. To stop seeing these errors, fix the underlying DNS issues.