Hi, my cluster seems to work fine, but when I submit a hive or sqoop job I get alerts (see screnshot). I already followed the recommendations of the post "how to get rid of ambari stale alerts", but they keep showing up... My cluster is running on vsphere virtual machines. Could this cause the problem. e.g. network is overloaded? ... View more

Hi, I am just getting into hadoop and HDFS. I am very confused how HDFS handles data loss, in case the NameNode fails. In the documentation i found three mechanisms to prevent data loss. Secondary NameNode, CheckpointNode and BackupNode. I understood the differences between them, but I am not sure if CheckpointNode and BackupNode are depreciated, since I cant find them in my Hortonworks distribution. I also understood, that none of them is neccessary if you deploy hadoop HA. Is there any guideline which of the nodes should be used in production? thank you for your answers ... View more