Kong dns requests to dns server decreases

[howan36]

version: kong:3.1.0

for Externalname type services, we just remove ports config like: # ports: # - port: 80, and we found the requests to dns server decreases nearly by half, so what dns mode may cause this happen?

[spacewander]

Could you give a full example so we can reproduce it?

[howan36]

kind: Service apiVersion: v1 metadata: name: service-default-service-default-dev-8080 namespace: kong spec: type: ExternalName externalName: default-service.default-dev ports:

• port: 8080

like the above config, i remove the last 2 lines

[spacewander]

Maybe Kong ingress controller generates different configuration for domain and for domain with port.

[howan36]

ok thanks for your reply, i guess maybe it's because some dns configurations will be different like dns stale ttl, i will check the KIC code to find if there're some details for it

[howan36]

i saw the configs from admin api like routes, services, targets, upstreams are just same, for 'with ports' and 'no ports' services, so if any other insights for it?

[howan36]

for example, if dns_valid_ttl dns_stale_ttl dns_cache_size, these 3 configurations would be different for them? maybe needs to further investigation

[spacewander]

Interesting. For 'with ports' and 'no ports' services, the configurations should be different since the upstream addresses are different...

[howan36]

i saw there is no port field for upstreams json data.

[howan36]

one more thing: there is no traffic, we also do not use maybe active and passive healthcheck, but there still lots of dns translation requests to coredns, what is it?

[chobits]

one more thing: there is no traffic, we also do not use maybe active and passive healthcheck, but there still lots of dns translation requests to coredns, what is it?

if you configure your host into target in some upstream, kong will automatically probe this host.

[howan36]

from admin api, i got the target like: {"data":[{"created_at":1754238438.816,"id":"d09638ca-0b83-52be-a68c-fcd0571b5419","tags":null,"upstream":{"id":"8c167dd3-7ffb-5b98-be0b-f25c0c02eead"},"target":"xxxxx-service.xxx.svc.cluster.local:8080","weight":100}],"next":null}%

[howan36]

your picture means that the target data should be the ip address?

[chronolaw]

@chobits do we have any updates? thanks.

[chobits]

I mean, if you don’t want Kong’s automatic background DNS resolution tasks to run, you should avoid configuring the backend host or IP as an upstream target entity. Instead, just set it as the host value of the service entity.

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This issue is marked as stale because it has been open for 14 days with no activity.

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