Help Center> Cloud Container Engine> FAQs> DNS FAQs> How Do I Optimize the Configuration If the External Domain Name Resolution Is Slow or Times Out?
Updated on 2022-08-15 GMT+08:00
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How Do I Optimize the Configuration If the External Domain Name Resolution Is Slow or Times Out?

The following is an example resolv.conf file for a container in a workload:

In the preceding information:

  • nameserver: IP address of the DNS. Set this parameter to the cluster IP address of CoreDNS.
  • search: domain name search list, which is a common suffix of Kubernetes.
  • ndots: If the number of dots (.) is less than the domain name, search is preferentially used for resolution.
  • timeout: timeout interval.
  • single-request-reopen: indicates that different source ports are used to send different types of requests.

By default, when you create a workload on the CCE console, the preceding parameters are configured as follows:

      dnsConfig:
        options:
          - name: timeout
            value: '2'
          - name: ndots
            value: '5'
          - name: single-request-reopen

These parameters can be optimized or modified based on service requirements.

Scenario 1: Slow External Domain Name Resolution

Optimization Solution

  1. If the workload does not need to access the Kubernetes Service in the cluster, see How Do I Configure a DNS Policy for a Container?.
  2. If the number of dots (.) in the domain name used by the working Service to access other Kubernetes Services is less than 2, set ndots to 2.

Scenario 2: External Domain Name Resolution Timeout

Optimization Solution

  1. Generally, the timeout of a Service must be greater than the value of timeout multiplied by attempts.
  2. If it takes more than 2s to resolve the domain name, you can set timeout to a larger value.
Parent topic: DNS FAQs

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