@irfangk1    That means you didn't install MySQL. Can I ask you one question? What documentation are you using as a reference?The basic steps are described when you are preparing the environment. To me it seems you launched the deployment using the embedded database Postgresql but now you want to switch to MySQL. To do that you need to install mysql and pre-create the ambari database before launching the Ambari server setup, that explains why you are getting all those errors. I can send you a procedure in 9 hours ... View more

@irfangk1  Can you share the screenshot of your Ambari Hive config  because when I see "jdbc:mysql://host.com/metastore" "hive"   that means you dont have  not The default   TCP port  for PostgreSQL is usually 5432 see in the postgresql.conf ... View more

@irfangk1  If you switched to Mysql why do you have these entries in your ambari.properties   server.jdbc.database=postgres server.jdbc.database_name=ambari server.jdbc.postgres.schema=ambari   Can you share the output of  # cat /etc/ambari-server/conf/ambari.properties | grep mysql Why is that in the log again I see  "jdbc:mysql://host.com/metastore" "hive"  where is the PORT  number?   ... View more

@irfangk1    This line in your error log says it all org.apache.ambari.server.DBConnectionVerification "jdbc:mysql://host.com/metastore" "hive" The format should be jdbc:mysql://host-name: port usually for Mysql it's 3306 to initiate any database connectivity you need to know the port at which the database is waiting for connections   Ambari.properties # cat /etc/ambari-server/conf/ambari.properties | grep mysql custom.mysql.jdbc.name=mysql-connector-java.jar previous.custom.mysql.jdbc.name=mysql-connector-java.jar server.jdbc.database=mysql server.jdbc.driver=com.mysql.jdbc.Driver server.jdbc.rca.driver=com.mysql.jdbc.Driver server.jdbc.rca.url=jdbc:mysql://your_host:3306/ambari server.jdbc.url=jdbc:mysql://your_host:3306/ambari Backup these files  Verification jar # mv /var/lib/ambari-agent/cache/DBConnectionVerification.jar /var/lib/ambari-agent/cache/DBConnectionVerification.jar.bck MySql connector  # mv /var/lib/ambari-agent/cache/mysql-connector-java.jar  /var/lib/ambari-agent/cache/mysql-connector-java.jar.bck Then restart Ambari and the agent    ... View more

@vsrikanth9    Great, it worked but you should recognize even if you had modified the     /var/kerberos/krb5kdc/kadm5.acl still  krb5.conf was wrong and your Ambari UI  was wrong so you still wouldn't have resolved it 🙂   Happy hadooping  ... View more

@vsrikanth9  Not exactly now the REALM part was wrong again the rest are okay you substituted  the wrong values here is how it's supposed to be you  see the highlighted part    Configuration snippets may be placed in this directory as well includedir /etc/krb5.conf.d/ [logging] default = FILE:/var/log/krb5libs.log kdc = FILE:/var/log/krb5kdc.log admin_server = FILE:/var/log/kadmind.log [libdefaults] dns_lookup_realm = false ticket_lifetime = 24h renew_lifetime = 7d forwardable = true rdns = false pkinit_anchors = /etc/pki/tls/certs/ca-bundle.crt default_realm = HADOOPSECURITY.COM default_ccache_name = KEYRING:persistent:%{uid} [realms] HADOOPSECURITY.COM = { kdc = p1.bigdata.com admin_server = p1.bigdata.com } [domain_realm] .hadoopsecurity.com = HADOOPSECURITY.COM hadoopsecurity.com = HADOOPSECURITY.COM   Do that and let me know the KDC and Admin server are usually the same 🙂 ... View more

@irfangk1  There are a couple of things to do first check your disk space and inode usage. To rule out permissions, there a are the listings for the relevant directory: $ ls -la /var/lib/mysql Can you share /var/log/mysql/mysql.log What the value of innodb-buffer-pool size in the config file /etc/mysql/my.cnf can you edit the my.cnf by adding   [mysqld] innodb_force_recovery = 1 And then running: sudo systemctl start mysql   Hope that helps   ... View more

@vsrikanth9  1.Your KDC part of the screenshot has an error 🙂 in the domains part just copy and paste the below as is to replace p1.bigdata.com noe the dot(.)  and comma separating the names .hadoopsecurity.com,hadoopsecurity.com   The validation passed because in reality it only test the connectivity ONLY to the KDC server   2. And then the Kadmin part the Admin principal should be the output of your   # kadmin.local Something like admin/admin@hadoopsecurity.com or root/admin@hadoopsecurity.com What ever you chose during the installation of Kerberos after that then launch the recreation of the keytabs and all should be okay. Make sure the KDC server is up and running during this process. Please revert   ... View more

@vsrikanth9    Your krb5.conf entry is wrong  please change it to match the below   [domain_realm] .hadoopsecurity.com = HADOOPSECURITY.COM hadoopsecurity.com = HADOOPSECURITY.COM   The restart the kdc and kadmin # systemctl start krb5kdc.service # systemctl start kadmin.service That should resolve your problem Happy hadooping        ... View more

@irfangk1  There is something wrong I don't see the database entry in your ambari.server.properties  how will it bind ? Something like below server.jdbc.url=jdbc:postgresql://<HOSTNAME>:<PORT>/ambari?ssl=true Can you validate, you are using the embedded postgres right?   ... View more

@irfangk1    Can you share your ambari.server. properties and your /etc/hosts ... View more

@ThanhP  Good everything is perfect for you now 🙂 You ONLY execute sudo -u hdfs hdfs namenode -format  as a last resort because it's dangerous and not recommended to run that on production cluster as that [re-initializes] formats your Namenode hence deleting all your metadata stored on the NameNode.   Having said that the answer you accepted can't help a member who encounters the same issue "HDFS NameNode won't leave safemode" maybe you should un-accept it and accept your own answer as it's the more realistic answer . Happy hadooping    ... View more

@ThanhP  I can see you are accessing the web shell UI on 192.168.1.37 yet the sandbox is pointing to 172.18.0.2:8020. Now if you type in your browser http://192.168.1.37:1080/splash2.html you should land on the splash screen Choose the Ambari UI link , this should give you the normal Ambari user UI if you reset your password before as I had stated please use that admin/[password] combination and you will realize that none of the components are started HDFS, YARN, MR, HIVE, HBASE etc Note: some components are in maintenance mode unless you want any of them beware of the dependencies e.g ATLAS must have HBASE running etc.. that could explain why you got the error "Failed on connection error java.net.Connection" At a certain point during your startup, "Timeline Service V1.5" will error out with the message to do with "safemode on" get to the shell as hdfs $ hdfs dfsadmin -safemode get This should indicate it's ON so get it out of safemode $ hdfs dfsadmin -safemode leave And again use the option Ambari start all it will pick up from the last point of failure, after the components startup you can simply access them eg the name node UI will automatically point to http://sandbox-hdp.hortonworks.com:50070/dfshealth.html#tab-overview Please do that an revert ... View more

@ThanhP    What @Herman   was trying to explain is what happens in the background and you cannot influence or manually replicate the process.  The screenshots I attached are the best you can get to resolve the issue because the screenshots are from exactly the same sandbox you are using.   So follow those steps and revert ... View more

@erkansirin78    Great !! it worked out for you, If you found this answer addressed your question, please take a moment to log in and click the thumbs up button. That would be a great help to Cloudera Community to find the solution quickly for these kinds of errors and mark it as a solution ... View more