Hello ,   I administer a small production cluster (2NN, 7DN). I want to perform a cluster maintenance (OS & Security updates) which will require for all nodes to be rebooted. From what i read impala catalog and statestore services can be migrated to different nodes with no issues. What about HiveServer, metastore and our databases (mariadb) (single host)? Can their hosts be rebooted without overal cluster downtime or should we enable HA for them? Ideally we want to avoid downtime.     ... View more

Hello Everyone,   Do HDFS ACLs apply on impala queries? If, for example, I want to give read permissions on specific directories in HDFS to a specific user and I modify the appropriate ACLs using "hdfs dfs setfacl" on the mentioned directories, will the user have only SELECT permissions when querying the files? I want to avoid using Kerberos auth and Sentry service.    ... View more

Hello Everyone,   Is there a way to permit SELECT only impala queries in HUE without enabling and configuring Sentry service? (maybe in OS level) The problem with enabling Sentry is that I have to first enable Kerberos and before that renaming some of my nodes. There is the option to enable Sentry testing mode but Cloudera does not recommend that in production environments. ... View more

Hello, At the organization I work for we have a hadoop cluster. We recently purchased new datanodes to expand the cluster. The new datanodes have 12 disks (8TB) instead of 10 (6TB), as the older datanodes.  After some research (mainly this community) I came to understand that its not a requirement to have the same number of drives in each node or equally sized disks.  On each old datanode we have 8 hdfs partitions one for every disk. Should we create 10 hdfs partitions on each new datanode or create 8 volumes using the 10 disks? Should we utilize all the available storage? And if we do is there something specific we should monitor?   ... View more