jlpedrosa commented on a change in pull request #24702: [SPARK-27989] 
[Kubernetes] [Core] Added retries on the connection to the driver for k8s
URL: https://github.com/apache/spark/pull/24702#discussion_r292426146
 
 

 ##########
 File path: 
resource-managers/kubernetes/docker/src/main/dockerfiles/spark/Dockerfile
 ##########
 @@ -51,6 +51,8 @@ ENV SPARK_HOME /opt/spark
 
 WORKDIR /opt/spark/work-dir
 RUN chmod g+w /opt/spark/work-dir
+#Disable negative dns reslolution 
https://docs.oracle.com/javase/8/docs/technotes/guides/net/properties.html
+RUN sed -i -e 
's/networkaddress.cache.negative.ttl=10/networkaddress.cache.negative.ttl=0/g'  
/usr/lib/jvm/java-1.8-openjdk/jre/lib/security/java.security
 
 Review comment:
   Hi @skonto 
   For me any option is ok, the entrypoint for the container, I'll adapt to 
whatever you guys prefer. I am aware that the Dockerfile is only used in k8s, 
the train of thoughts is that this scenario is only common at k8s when pods 
networking may take some time (CNI, Sidecar pods..). Just let me know what is 
the path you preffer and I'll implement in such way.
   In the docker image that spark uses (the base [spark 
image](https://github.com/apache/spark/blob/1217996f1574f758d8cccc1c4e3846452d24b35b/resource-managers/kubernetes/docker/src/main/dockerfiles/spark/Dockerfile#L18)
 is openjdk8 alpine 
[openjdk8](https://github.com/docker-library/openjdk/blob/178c542fbb93a8f8a42e331b73a1214c9d8ba81d/8/jdk/alpine/Dockerfile#L7))
  dns caching is disabled, if you'd start an openjdk8 image and your try:
   `watch -n 2 ping -c 1  www.apache.org`
   while tcpdumping, you'll see that every 2 seconds a request is issued.
   I tried this also in an ubtuntu docker image, and I get the same behaviour.
   
   @skonto @srowen: Just let me know the way you'd prefer it and I'll patch it 
that way.
   

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