hdfsIntegrationTest is failing due to DisallowedDatanodeException

beam_PostCommit_Python_Verify is perma red due to this.

https://scans.gradle.com/s/pqg3ent77c2pu/console-log?task=:beam-sdks-python:hdfsIntegrationTest#L1653

 
namenode_1_d5b2d221b2e2 | org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException: Datanode denied communication with
namenode because hostname cannot be resolved (ip=172.18.0.3, hostname=172.18.0.3): DatanodeRegistration(0.0.0.0:50010, datanodeUuid=717d9e8f-ff6b-449c-bc94-6deb57455f93, infoPort=50075, infoSecurePort=0, ipcPort=50020, storageInfo=lv=-57;cid=CID-ef5ccec9-8245-45cc-9cc1-b103684e8ce1;nsid=1522131886;c=1542034438259)
 
 
[33mdatanode_1_3ee1bc415f49 | 18/11/10 18:03:06 ERROR datanode.DataNode: Initialization failed for Block pool BP-15607
62326-172.18.0.2-1541872973618 (Datanode Uuid 367ac165-40b3-437f-97dc-567cb8d15da5) service to namenode/172.18.0.2:8020 Datanode denied communication with namenode because hostname cannot be resolved (ip=172.18.0.3, hostname=172.18.0.3): DatanodeRegistration(0.0.0.0:50010, datanodeUuid=367ac165-40b3-437f-97dc-567cb8d15da5, infoPort=50075, infoSecurePort=0, ipcPort=50020, storageInfo=lv=-57;cid=CID-d00d4259-9d80-4952-85d1-a0012d91842d;nsid=1271723208;c=1541872973618)
 
Udi, any idea ?

cc: swegner altay