"Error: Key not loaded" in h2o deployed through a K3s cluster, using python3 client - python-3.x

Question

I can confirm the 3-replica cluster of h2o inside K3s is correctly deployed, as executing in the Python3 interpreter h2o.init(ip="x.x.x.x") works as expected. I followed the instructions noted here: https://www.h2o.ai/blog/running-h2o-cluster-on-a-kubernetes-cluster/
Nevertheless, I had to modify the service.yaml and comment out the line which says clusterIP: None, as K3s was complaining about something related to its inability to set the clusterIP to None. But even though, I can certify it is working correctly, and I am able to use an external IP to connect to the cluster.
If I try to load the dataset using the h2o cluster inside the K3s cluster using the exact same steps as described here http://docs.h2o.ai/h2o/latest-stable/h2o-docs/automl.html, this is the output that I get:
>>> train = h2o.import_file("https://s3.amazonaws.com/erin-data/higgs/higgs_train_10k.csv")
...
h2o.exceptions.H2OResponseError: Server error java.lang.IllegalArgumentException:
Error: Key not loaded: Key<Frame> https://s3.amazonaws.com/erin-data/higgs/higgs_train_10k.csv
Request: POST /3/ParseSetup
data: {'check_header': '0', 'source_frames': '["https://s3.amazonaws.com/erin-data/higgs/higgs_train_10k.csv"]'}
The same error occurs if I use the h2o.upoad_file("x.csv") method.
There is a clue about what may be happening here: Key not loaded: Key<Frame> while POSTing source frame through ParseSetup in H2O API call but I am not using curl, and I can not find any parameter that could help me overcome this issue: http://docs.h2o.ai/h2o/latest-stable/h2o-py/docs/h2o.html?highlight=import_file#h2o.import_file
I need to use the Python client inside the same K3s cluster due to different technical reasons, so I am not able to kick off nor Flow nor Firebug to know what may be happening.
I can confirm it is working correctly when I simply issue a h2o.init(), using the local Java instance.
UPDATE 1:
I have tried in different K3s clusters without success. I changed the service.yaml to a NodePort, and now this is the error traceback:
>>> train = h2o.import_file("https://s3.amazonaws.com/erin-data/higgs/higgs_train_10k.csv")
...
h2o.exceptions.H2OResponseError: Server error java.lang.IllegalArgumentException:
Error: Job is missing
Request: GET /3/Jobs/$03010a2a016132d4ffffffff$_a2366be93ec99a78d7bc161de8c54d67
UPDATE 2:
I have tried using different services (NodePort, LoadBalancer, ClusterIP) and none of them work. I also have tried using Minikube with the official image, and with a custom image made by me, without success. I suspect this is something related to either h2o itself, or the clustering between pods. I will keep digging and let's think there will be some gold in it.
UPDATE 3:
I also found out that the post about running H2O in Docker is really outdated https://www.h2o.ai/blog/h2o-docker/ nor is working the Dockerfile present at GitHub (I changed it to uncomment the ENTRYPOINT section without success): https://github.com/h2oai/h2o-3/blob/master/Dockerfile
Even though, I tried with the custom image I built for h2o-k8s and it is working seamlessly in pure Docker. I am wondering why it is still not working in K8s...
UPDATE 4:
I have tried modifying the environment variable called H2O_KUBERNETES_SERVICE_DNS without success.
In the meantime, the cluster started to be unavailable, that is, the readinessProbe's would not successfully complete. No matter what I change now, it does not work.
I spinned up a K3d cluster in local to see what happened, and surprisingly, the readinessProbe's were not failing, using v3.30.0.6. But now I started testing it with R instead of Python. I am glad I tried, because I may have pinpointed what was wrong. There is a version mismatch between the client and the server. So I updated accordingly the image to v3.30.0.1.
But now again, the readinessProbe is not working in my k3d cluster, so I am unable to test it.

Answer 1

It seems it is working now. R client version 3.30.0.1 with server version 3.30.0.1. Also tried with Python version 3.30.0.7 and server version 3.30.0.7 and it started working. Marvelous. The problem was caused by a version mismatch between the client and the server, as the python client was updated to 3.30.0.7 while the latest server for docker was 3.30.0.6.