[jira] [Created] (FLINK-24237) Consider disabling or lowering DNS caching timeout in docker image

["Chesnay Schepler (Jira)" <ji...@apache.org>]

Chesnay Schepler created FLINK-24237:
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             Summary: Consider disabling or lowering DNS caching timeout in docker image
                 Key: FLINK-24237
                 URL: https://issues.apache.org/jira/browse/FLINK-24237
             Project: Flink
          Issue Type: Improvement
          Components: Deployment / Kubernetes
            Reporter: Chesnay Schepler
             Fix For: 1.15.0


A recent [blog post|https://mux.com/blog/5-years-of-flink-at-mux/] by Mux mentions that they have disabled DNS caching in their docker image because without it the Flink processes had trouble talking to over services when deployments move between nodes:

??The JVM will cache DNS entries forever by default. This is undesirable in Kubernetes deployments where there’s an expectation that DNS entries can and do change frequently as pod deployments move between nodes. We’ve seen Flink applications suddenly unable to talk to other services in the cluster after pods are upgraded.??

We should investigate this, in particular whether it would make sense to set it to a low value instead of disabling it entirely.



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