Understanding the Main Concept
By asking the PolarDNS server to resolve something, you are essentially giving it instructions how it should respond to you. This means that you (the client) dictate the PolarDNS server what kind of response it should produce for you.
For instance, consider the following query:
dig always.ttl2000000000.slp1500.yourdomain.com @127.0.0.1
You should receive an A record with the 2.3.4.5 IP address again, but this time with a TTL value of 2,000,000,000 (63.4 years) and after a delay of 1.5 seconds:
In the above example, we have used the always basic feature (which always resolves to something), and combined it with the ttl modifier to adjust the TTL value and the slp modifier to wait before sending the response out.