Pod host name takes 30 seconds to resolve
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
StarlingX |
Fix Released
|
Medium
|
Cole Walker |
Bug Description
Brief Description
-----------------
Coredns is caching negative responses for 30 seconds, resulting in a long wait period before pod names can be resolved if a pod starts up right after a negative response is cached.
Severity
--------
Minor: System/Feature is usable with minor issue
Steps to Reproduce
------------------
From within a running pod, attempt to resolve the name of a pod that does not exist
/ # nslookup <non-existant pod FQDN >
-> Fails as expected
Immediately start a new pod with the FQDN used above
From within the original pod, continue attempting to resolve the name
Name lookup will fail for 30 seconds even though the new pod is running and can be pinged by ip address, until the negative cache entry expires
Expected Behavior
------------------
Name should be resolvable shortly after a pod starts up
Actual Behavior
----------------
Name resolution takes 30 seconds
Reproducibility
---------------
100%
System Configuration
-------
Any
Branch/Pull Time/Commit
-------
stx master
Last Pass
---------
New scenario
Timestamp/Logs
--------------
Attach the logs for debugging (use attachments in Launchpad or for large collect files use: https:/
Provide a snippet of logs here and the timestamp when issue was seen.
Please indicate the unique identifier in the logs to highlight the problem
Workaround
----------
Manually modify the coredns negative caching behaviour.
Changed in starlingx: | |
assignee: | nobody → Cole Walker (cwalops) |
Changed in starlingx: | |
importance: | Undecided → Medium |
status: | New → Triaged |
tags: | added: stx.5.0 stx.containers |
Fixed by https:/ /review. opendev. org/c/starlingx /ansible- playbooks/ +/765590
Merged on 2020-12-08