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<div class="block-paragraph_advanced"><a href="https://cloud.google.com/kubernetes-engine">Google Kubernetes Engine</a> (GKE) offers two different ways to perform <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery">service discovery and DNS resolution</a>: the in-cluster kube-dns functionality, and GCP managed <a href="https://cloud.google.com/dns">Cloud DNS</a>. Either approach can be combined with the performance-enhancing NodeLocal DNSCache add-on. 
New GKE Autopilot clusters use Cloud DNS as a fully managed DNS solution for your GKE Autopilot clusters without any configuration required on your part. But for GKE Standard clusters, you have the following DNS provider choices:
<ol>
<li aria-level="1" style="list-style-type: decimal; vertical-align: baseline;">
<a href="https://cloud.google.com/kubernetes-engine/docs/how-to/kube-dns">Kube-dns</a> (default) 
</li>
<li aria-level="1" style="list-style-type: decimal; vertical-align: baseline;">
<a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns">Cloud DNS</a> -  configured for either cluster-scope or VPC scope, and 
</li>
<li aria-level="1" style="list-style-type: decimal; vertical-align: baseline;">
Install and run your own DNS  (like Core DNS)
</li>
</ol>
In this blog, we break down the differences between the DNS providers for your GKE Standard clusters, and guide you to the best solution for your specific situation. 
<h3>Kube-DNS </h3></div>
<div class="block-image_full_width">

</div>
 </div>

</div>
<div class="block-paragraph_advanced"><a href="https://cloud.google.com/kubernetes-engine/docs/how-to/kube-dns">kube-dns</a> is the default DNS provider for Standard GKE clusters, providing DNS resolution for services and pods within the cluster. If you select this option, GKE deploys the necessary kube-dns components such as Kube-dns pods, Kube-dns-autoscaler, Kube-dns configmap and Kube-dns service in the kube-system namespace.
kube-dns is the default DNS provider for GKE Standard clusters and the only DNS provider for Autopilot clusters running versions earlier than 1.25.9-gke.400 and 1.26.4-gke.500.
Kube-dns is a suitable solution for workloads with moderate DNS query volumes that have stringent DNS resolution latency requirements (e.g. under ~2-4ms). Kube-dns is able to provide low latency DNS resolution for all DNS queries as all the DNS resolutions are performed within the cluster.
If you notice DNS timeouts or failed DNS resolutions for bursty workload traffic patterns when using kube-dns, consider scaling the number of kube-dns pods, and enabling NodeLocal DNS cache for the cluster. You can scale the number of kube-dns pods beforehand using <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/nodelocal-dns-cache#scaling_up_kube-dns">Kube-dns autoscaler</a>, and manually tuning it to the cluster's DNS traffic patterns. Using kube-dns along with Nodelocal DNS cache (discussed below) also reduces overhead on the kube-dns pods for DNS resolution of external services. 
While scaling up kube-dns and using NodeLocal DNS Cache(NLD)  helps in the short term, it does not guarantee reliable DNS resolution during sudden traffic spikes. Hence migrating to Cloud DNS provides a more robust and long-term solution for improved reliability of DNS resolution consistently across varying DNS query volumes. You can update the DNS provider for your existing GKE Standard from <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns">kube-dns to Cloud DNS</a> without requiring to re-create your existing cluster. 
For logging the DNS queries when using kube-dns, there is manual effort required in creating a new <a href="https://cloud.google.com/knowledge/kb/enable-dns-queries-log-in-google-kubernetes-engine-000004855">kube-dns debug pod</a> with log-queries enabled. 
<h3>Cloud DNS</h3>
<a href="https://cloud.google.com/dns/docs/overview/">Cloud DNS</a> is a Google-managed service that is designed for high scalability and availability. In addition, Cloud DNS elastically scales to adapt to your DNS query volume, providing consistent and reliable DNS query resolution regardless of traffic volume. Cloud DNS simplifies your operations and minimizes operational overhead since it is a Google managed service and does not require you to maintain any additional infrastructure. Cloud DNS supports dns resolutions across the entire VPC, which is something not currently possible with kube-dns.
Also, while using <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/multi-cluster-services">Multi Cluster Services</a> (MCS) in GKE, Cloud DNS provides DNS resolution for services across your <a href="https://cloud.google.com/anthos/fleet-management/docs">fleet of clusters</a>.</div>
<div class="block-image_full_width">

</div>
 </div>

</div>
<div class="block-paragraph_advanced">Unlike kube-dns, Google Cloud’s hosted DNS service <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns">Cloud DNS</a> provides Pod and Service DNS resolution that auto-scales and offers a <a href="https://cloud.google.com/dns/sla">100% service-level agreement</a>, reducing DNS timeouts and providing consistent DNS resolution latency for heavy DNS workloads.
Cloud DNS also integrates with <a href="https://cloud.google.com/dns/docs/monitoring">Cloud Monitoring</a>, giving you greater visibility into DNS queries for enhanced troubleshooting and analysis. 
The Cloud DNS controller automatically provisions DNS records for pods and services in Cloud DNS for ClusterIP, headless and external name services. 
You can configure Cloud DNS to provide GKE DNS resolution in either <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#vpc_scope_dns">VPC</a> or <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns">Cluster</a> (the default) scope. With VPC scope, the DNS records are resolvable with the entire VPC. This is achieved with the private DNS zone that gets created automatically. With Cluster scope, the DNS records are resolvable only within the cluster.
While Cloud DNS offers enhanced features, it does come with <a href="https://cloud.google.com/dns/pricing">usage-based costs</a>. You save on compute costs and overhead by removing kube-dns pods when using Cloud DNS. Considering the typical cluster size workload traffic patterns, Cloud DNS is usually more cost effective than running kube-dns
You can <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns">migrate clusters from kube-dns to Cloud</a> DNS cluster scope without downtime or changes to your applications. The reverse (migrating from Cloud DNS to kube-dns) is not a seamless operation.
<h3>NodeLocal DNSCache</h3></div>
<div class="block-image_full_width">

</div>
 </div>

</div>
<div class="block-paragraph_advanced"><a href="https://cloud.google.com/kubernetes-engine/docs/how-to/nodelocal-dns-cache#architecture">NodeLocal DNSCache</a> is a GKE add-on that you can run in addition to <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery">kube-dns</a> and Cloud DNS. The node-local-dns pod gets deployed on the GKE nodes after the option has been enabled (subject to a node upgrade procedure). 
Nodelocal DNS Cache (NLD) helps to reduce the average DNS resolution times by resolving the DNS requests locally on the same nodes as the pods, and only forwards requests that it cannot resolve to the other DNS servers in the cluster. This is a great fit for clusters that have heavy internal DNS query loads. 
Enable NLD during maintenance windows. Please note that node pools must be re-created for this change to take effect.
<h3>Final thoughts</h3>
The choice of DNS provider for your GKE Standard cluster has implications for the performance and reliability, in addition to your operations and overall service discovery architecture.  Hence, it is crucial for GKE Standard users to understand their DNS options taking into account their application and architecture objectives. Standard GKE clusters allow you to use either kube-dns or Cloud DNS as your DNS provider,  allowing you to optimize for either low latency DNS resolution or a simple, scalable and reliable DNS solution for GKE Standard clusters. You can learn more about DNS for your GKE cluster from the <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery">GKE documentation </a>. If you have any further questions, feel free to <a href="https://cloud.google.com/contact/?_gl=1*11nzsgc*_up*MQ..&amp;gclid=CjwKCAjwkuqvBhAQEiwA65XxQLJotHHWHX6hkVrSeba0VuZxzHaRaPWL-3-Jk5LLIRDWWC5-N8iYbxoC5wkQAvD_BwE&amp;gclsrc=aw.ds">contact us</a>.
<hr/>
We thank the Google Cloud team member who contributed to the blog: Selin Goksu, Technical Solutions Developer, Google</div>

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--- !ruby/object:Feedjira::Parser::RSSEntry
published: 2024-04-03 16:00:00.000000000 Z
carlessian_info:
 news_filer_version: 2
 newspaper: Google Cloud Blog
 macro_region: Technology
entry_id: !ruby/object:Feedjira::Parser::GloballyUniqueIdentifier
 guid: https://cloud.google.com/blog/products/networking/understanding-dns-options-for-gke/
title: DNS providers for Google Kubernetes Engine explained
categories:
- Containers & Kubernetes
- GKE
- Developers & Practitioners
- Networking
summary: "<div class=\"block-paragraph_advanced\"><a href=\"https://cloud.google.com/kubernetes-engine\">Google Kubernetes
 Engine</a> (GKE) offers two different
 ways to perform <a href=\"https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery\">service discovery
 and DNS resolution</a>: the in-cluster
 kube-dns functionality, and GCP managed <a href=\"https://cloud.google.com/dns\">Cloud DNS</a>. Either approach can be combined with the performance-enhancing
 NodeLocal DNSCache add-on. \nNew
 GKE Autopilot clusters use Cloud DNS as a fully managed DNS solution for your GKE
 Autopilot clusters without any configuration required on your part. But for GKE
 Standard clusters, you have the following DNS provider choices:\n<ol>\n<li
 aria-level=\"1\" style=\"list-style-type: decimal; vertical-align: baseline;\">\n<a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/kube-dns\">Kube-dns</a> (default) \n</li>\n<li aria-level=\"1\"
 style=\"list-style-type: decimal; vertical-align: baseline;\">\n<a
 href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns\">Cloud DNS</a> -  configured for either cluster-scope or VPC
 scope, and \n</li>\n<li aria-level=\"1\" style=\"list-style-type: decimal;
 vertical-align: baseline;\">\nInstall and run your own DNS  (like Core DNS)\n</li>\n</ol>\nIn this blog, we break down the differences
 between the DNS providers for your
 GKE Standard clusters, and guide
 you to the best solution for your specific situation. \n<h3>Kube-DNS </h3></div>\n<div class=\"block-image_full_width\">\n\n\n\n\n\n\n
 \ \n <div class=\"article-module h-c-page\">\n <div class=\"h-c-grid\">\n
 \ \n\n <figure class=\"article-image--large\n \n \n h-c-grid__col\n
 \ h-c-grid__col--6 h-c-grid__col--offset-3\n \n \n \"\n
 \ >\n\n \n \n \n <img\n src=\"https://storage.googleapis.com/gweb-cloudblog-publish/images/1_gZbgxg4.max-1000x1000.png\"\n
 \ \n alt=\"1\">\n \n </a>\n \n </figure>\n\n
 \ \n </div>\n </div>\n \n\n\n\n\n</div>\n<div class=\"block-paragraph_advanced\"><a
 href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/kube-dns\">kube-dns</a> is the default DNS provider for Standard GKE clusters, providing DNS
 resolution for services and pods within the cluster. If you select this option,
 GKE deploys the necessary kube-dns components such as Kube-dns pods, Kube-dns-autoscaler,
 Kube-dns configmap and Kube-dns service in the kube-system namespace.\nkube-dns is the default DNS provider for GKE
 Standard clusters and the only DNS provider for Autopilot clusters running versions
 earlier than 1.25.9-gke.400 and 1.26.4-gke.500.\nKube-dns is a suitable solution for workloads with moderate DNS query
 volumes that have stringent DNS
 resolution latency requirements (e.g. under ~2-4ms). Kube-dns is able to provide
 low latency DNS resolution for all DNS queries as all the DNS resolutions are performed within the cluster.\nIf you notice DNS timeouts or failed DNS resolutions
 for bursty workload traffic patterns when using kube-dns, consider scaling the number
 of kube-dns pods, and enabling NodeLocal DNS cache for the cluster. You can scale the
 number of kube-dns pods beforehand using
 <a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/nodelocal-dns-cache#scaling_up_kube-dns\">Kube-dns autoscaler</a>, and manually tuning it to the cluster's DNS
 traffic patterns. Using kube-dns along with Nodelocal DNS cache (discussed below)
 also reduces overhead on the kube-dns pods for DNS resolution of external services. \nWhile scaling up kube-dns and using NodeLocal
 DNS Cache(NLD)  helps in the short term, it does not guarantee reliable DNS resolution
 during sudden traffic spikes. Hence migrating to Cloud DNS provides a more robust
 and long-term solution for improved reliability
 of DNS resolution consistently across varying DNS query volumes. You can update the DNS provider for your existing GKE Standard from
 <a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns\">kube-dns to Cloud
 DNS</a> without requiring to re-create
 your existing cluster. \nFor
 logging the DNS queries when using kube-dns, there is manual effort required in
 creating a new <a href=\"https://cloud.google.com/knowledge/kb/enable-dns-queries-log-in-google-kubernetes-engine-000004855\">kube-dns debug pod</a> with log-queries enabled. \n<h3>Cloud DNS</h3>\n<a href=\"https://cloud.google.com/dns/docs/overview/\">Cloud DNS</a> is a Google-managed service
 that is designed for high scalability and availability. In addition, Cloud DNS elastically scales to adapt to your DNS query
 volume, providing consistent and reliable DNS query resolution regardless of traffic
 volume. Cloud DNS simplifies your operations and minimizes operational overhead
 since it is a Google managed service and does not require you to maintain any additional
 infrastructure. Cloud DNS supports
 dns resolutions across the entire VPC, which is something not currently possible
 with kube-dns.\nAlso, while
 using <a href=\"https://cloud.google.com/kubernetes-engine/docs/concepts/multi-cluster-services\">Multi Cluster Services</a> (MCS) in GKE, Cloud DNS provides DNS resolution for services across your <a
 href=\"https://cloud.google.com/anthos/fleet-management/docs\">fleet of clusters</a>.</div>\n<div class=\"block-image_full_width\">\n\n\n\n\n\n\n
 \ \n <div class=\"article-module h-c-page\">\n <div class=\"h-c-grid\">\n
 \ \n\n <figure class=\"article-image--large\n \n \n h-c-grid__col\n
 \ h-c-grid__col--6 h-c-grid__col--offset-3\n \n \n \"\n
 \ >\n\n \n \n \n <img\n src=\"https://storage.googleapis.com/gweb-cloudblog-publish/images/2_b9PLEA8.max-1000x1000.png\"\n
 \ \n alt=\"2\">\n \n </a>\n \n </figure>\n\n
 \ \n </div>\n </div>\n \n\n\n\n\n</div>\n<div class=\"block-paragraph_advanced\">Unlike kube-dns, Google Cloud’s hosted DNS service
 <a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns\">Cloud DNS</a> provides Pod and Service DNS resolution that
 auto-scales and offers a <a href=\"https://cloud.google.com/dns/sla\">100% service-level
 agreement</a>, reducing DNS timeouts
 and providing consistent DNS resolution
 latency for heavy DNS workloads.\nCloud DNS also integrates with <a href=\"https://cloud.google.com/dns/docs/monitoring\">Cloud Monitoring</a>, giving you greater visibility into DNS queries
 for enhanced troubleshooting and analysis. \nThe Cloud DNS controller automatically provisions DNS records for pods
 and services in Cloud DNS for ClusterIP, headless and external name services. \nYou can configure Cloud DNS to provide GKE DNS
 resolution in either <a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#vpc_scope_dns\">VPC</a> or <a href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns\">Cluster</a> (the default) scope. With VPC scope, the DNS
 records are resolvable with the entire VPC. This is achieved with the private DNS
 zone that gets created automatically. With Cluster scope, the DNS records are resolvable
 only within the cluster.\nWhile
 Cloud DNS offers enhanced features, it does come with <a href=\"https://cloud.google.com/dns/pricing\">usage-based costs</a>. You save on compute costs and overhead by
 removing kube-dns pods when using Cloud DNS. Considering the typical cluster size
 workload traffic patterns, Cloud DNS is usually more cost effective than running
 kube-dns\nYou can <a
 href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/cloud-dns#cluster_scope_dns\">migrate clusters
 from kube-dns to Cloud</a> DNS
 cluster scope without downtime or changes to your applications. The reverse (migrating from Cloud DNS to kube-dns) is not a seamless
 operation.\n<h3>NodeLocal
 DNSCache</h3></div>\n<div class=\"block-image_full_width\">\n\n\n\n\n\n\n
 \ \n <div class=\"article-module h-c-page\">\n <div class=\"h-c-grid\">\n
 \ \n\n <figure class=\"article-image--large\n \n \n h-c-grid__col\n
 \ h-c-grid__col--6 h-c-grid__col--offset-3\n \n \n \"\n
 \ >\n\n \n \n \n <img\n src=\"https://storage.googleapis.com/gweb-cloudblog-publish/images/3_njIGHJZ.max-1000x1000.png\"\n
 \ \n alt=\"3\">\n \n </a>\n \n </figure>\n\n
 \ \n </div>\n </div>\n \n\n\n\n\n</div>\n<div class=\"block-paragraph_advanced\"><a
 href=\"https://cloud.google.com/kubernetes-engine/docs/how-to/nodelocal-dns-cache#architecture\">NodeLocal DNSCache</a> is a GKE add-on that you can run in addition
 to <a href=\"https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery\">kube-dns</a> and Cloud DNS. The node-local-dns pod gets
 deployed on the GKE nodes after the option has been enabled (subject to a node upgrade
 procedure). \nNodelocal
 DNS Cache (NLD) helps to reduce the average DNS resolution times by resolving the
 DNS requests locally on the same nodes as the pods, and only forwards requests that
 it cannot resolve to the other DNS servers in the cluster. This is a great fit for
 clusters that have heavy internal DNS query loads. \nEnable NLD during maintenance windows. Please note that node pools must
 be re-created for this change to take effect.\n<h3>Final thoughts</h3>\nThe
 choice of DNS provider for your GKE Standard cluster has implications for the performance
 and reliability, in addition to your operations and overall service discovery architecture. 
 Hence, it is crucial for GKE Standard
 users to understand their DNS options taking into account their application and
 architecture objectives. Standard
 GKE clusters allow you to use either kube-dns or Cloud DNS as your DNS provider, 
 allowing you to optimize for either low latency DNS resolution or a simple, scalable
 and reliable DNS solution for GKE Standard clusters. You can learn more about DNS
 for your GKE cluster from the <a href=\"https://cloud.google.com/kubernetes-engine/docs/concepts/service-discovery\">GKE documentation
 </a>. If you have any further questions,
 feel free to <a href=\"https://cloud.google.com/contact/?_gl=1*11nzsgc*_up*MQ..&amp;gclid=CjwKCAjwkuqvBhAQEiwA65XxQLJotHHWHX6hkVrSeba0VuZxzHaRaPWL-3-Jk5LLIRDWWC5-N8iYbxoC5wkQAvD_BwE&amp;gclsrc=aw.ds\">contact us</a>.\n<hr/>\nWe thank the Google Cloud team member who contributed
 to the blog: Selin Goksu, Technical
 Solutions Developer, Google</div>"
rss_fields:
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url: https://cloud.google.com/blog/products/networking/understanding-dns-options-for-gke/
author: Indrabhushan Shukla

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