@ThanhP  Good to know that the issue is resolved.   If your question is answered then, Please make sure to mark the answer as the accepted solution. If you find a reply useful, say thanks by clicking on the thumbs up button. ... View more

@ThanhP The following error indicates that Ambari is not able to connect to the MySQL DB instance. Caused by: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. Most possible cause might be either there is some network issue of your MySQL might not be running properly (running with errors). We might need to review Mysql side log as well.   Checks from AmbariServer Host side So can you please check if you have entered correct DB url in ambari.properties? Can you please share the following output? # grep 'jdbc' /etc/ambari-server/conf/ambari.properties In the output of the above command we shoudl be able to see the MySQL DB details like user/URl/driver ..etc Can you please try running the following simple JDBC connectivity check from Ambari DB host to the MySQL instance? # /usr/jdk64/jdk1.8.0_112/bin/java -cp /var/lib/ambari-server/resources/DBConnectionVerification.jar:/usr/share/java/mysql-connector-java.jar org.apache.ambari.server.DBConnectionVerification "jdbc:mysql://xxxxxxxxx/ambari" "ambariDBUser" "ambariDBPassword" com.mysql.jdbc.Driver You will need to change the 'ambariDBUser'/ 'ambariDBPassword' and DB url based on the ambari.properties entries. Also from the ambari server host can you please check if the MySQL host&port is accessible without any issue? This is to isolate if the MySQL host & port is accessible from Ambari server host? # telnet $MYSQL_HOSTNAME 3306 (OR) # nc -v $MYSQL_HOSTNAME 3306   Checks from MySQL DB side Please try to restart MySQL DB once. Check if the MySQL is listening to the correct port ? (default port is 3306) # ps -ef | grep mysql # netstat -tnlpa | grep 3306 # netstat -tnlpa | grep `cat /var/run/mysqld/mysqld.pid` For any errors on Mysql side we can check the MySQL log like '# less /var/log/mysqld.log' ... View more

@moritz    By running the following command , you are telling Ambari to use an Existing Postgres DB instance in this case ambari will expect you to create the Db user and setup the DB schema on your own inside the PostgresDB (ambari will not do it for you). # sudo ambari-server setup --java-home /usr/lib/jvm/java-1.8.0-openjdk/jre --enable-lzo-under-gpl-license --database=postgres --databasehost=localhost --databaseport=5432 --databasename=ambari --postgresschema=ambari --databaseusername=ambari --databasepassword=ambari --jdbc-db=postgres --jdbc-driver=/usr/share/java/postgresql-jdbc.jar Using existing Postgres DB instance for Ambari DB means we will need to make sure that After running the above "setup" command and before running the "start" command you already have performed the following task on your Postgres Database explicitly. https://docs.cloudera.com/HDPDocuments/Ambari-2.7.3.0/administering-ambari/content/amb_using_ambari_with_postgresql.html   Are you sure that before starting Ambari DB you had performed the instructions mentioned in the above link? If you want Ambari to setup the PostgresDB (create DB user/ create various tables ..etc) for you then you may want to run the setup command without specifying the Postgres DB details so that ambari will think that it has to setup the Postgres DB for you in the Localhost with default settings like. default ambari DB username will be "ambari" default Postgres Db password will. be "bigdata" ...etc # sudo ambari-server setup --java-home /usr/lib/jvm/java-1.8.0-openjdk/jre --enable-lzo-under-gpl-license -s   . ... View more

@ranger  Even if you have build ranger from source... before making the API call you should validate the following:   Are you really sure that the credentials that you are entering is correct?   1. Are you able to login to Ranger UI with that credential?  (this is the verify if your credentials are correct or not) ?       2. Do you see "Bad Credentials" message inside the "xa_portal.log" ?  Can you share the log?     ... View more

@Manoj690  You might want to look at this thread: https://community.cloudera.com/t5/Support-Questions/Configuring-hive-users-in-admin-role/m-p/236802   ... View more

@Manoj690  The terminal where you are trying to run the query . can you switch to "hive" user?   # su - hive ... View more