We are trying to connect from several windows severs to a hadoop cluster. Authentication is via Kerberos. On one terminal server we are using the MIT Kerberos ticket manager (a bunch of users), on others not (only one technical user). From time to time connections fail, mostly with the information that the server is not reachable and we shall check if we have permissions to access the database. Sometimes changing one value in the registry and return to old value helps, Sometimes not. Not even a restart. On some server we have scheduled as task recurring every 15 minutes. e.g 5 times it works, 3 times not and then it works again. For secure we have set MaxPacketSize to 1 in order to force using tcp. In the logs we see mostly this information: java.lang.RuntimeException: [Cloudera][ImpalaODBC] (120) Error while retrieving data from in Impala: [08S01] : ImpalaThriftAPICallFailed  There is no loadbalancer is use, we are connecting directly to the nodes. Two nodes are configured as KDC (Linux Kerberos).   Every part (Hadoopteam - Kerberosteam) says all is working fine.       ... View more