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memodi
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jpinsonneau
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Looks good, thanks @memodi !
Co-authored-by: Amogh Rameshappa Devapura <aramesha@redhat.com>
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| Short DNS names for cluster services causes high load on the cluster DNS service |
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typo
| Short DNS names for cluster services causes high load on the cluster DNS service | |
| Short DNS names for cluster services cause high load on the cluster DNS service |
| resulting in higher latencies, negative caching and increased dns traffic. This | ||
| negative impact can be prevented by using Fully Qualified Domain Name (FQDN) in | ||
| the requests. After updating the hostname to `nginx.server.svc.cluster.local.` | ||
| in the curl requests, we are not seeing any NXDOMAINS and reduced unnecessary | ||
| dns traffic in our cluster. You can imagine the performance impact if such | ||
| configuration issue propagated to hundreds of services in your cluster. | ||
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"DNS" is sometimes written in capitals sometimes not, I would suggest to stick to just one form (across the full post)
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| Short DNS names for cluster services causes high load on the cluster DNS service | ||
| resulting in higher latencies, negative caching and increased dns traffic. This |
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the way "negative caching" is mentioned here may trigger questions from the reader (what is it etc.) ; maybe we can expand a little bit this section, saying that the DNS resolver has that mechanism of negative caching to avoid consistently re-emitting queries to known non-existing domains - which is actually also a remediation to avoid unnecessary queries - but not as good as just using fqdn with trailing dot
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I added text for negative caching in parentheses, wdyt?
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thanks, text sounds good, just a little character issue in —like NXDOMAIN- (there's a long and a short dash)
| issues, it comes with some caveats to favor performance. This feature isn't | ||
| supported with Prometheus as datastore since storing DNS names as metric values | ||
| could cause high cardinality. That means, if you're looking to use this feature |
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On cardinality, maybe we can tell that we're currently evaluating the impact - see my comment here - I think eventually we can add that to the metrics
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/lgtm |
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@memodi you can merge when you want |
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DNS name tracking blog