I tried to upgrade HDP from 2.4.2 to 2.5.3 and encountered an error "There is no active namenodes". The problem is described here namenode-restart-fails-during-hdp-upgrade
So I decided to do Downgrade and increase the timeout. However, after the downgrade Ambari doesn't start because of "DB configs consistency check failed." I guess the bag is Downgrade Can Create Multiple Mappings For Latest Configs
Recovery from backup failed.
How can I solve this problem?
HDP-22.214.171.124 Ambari 126.96.36.199 Postgres 8.4.20
ERROR - You have config(s), in cluster development, that is(are) selected more than once in clusterconfigmapping table: ams-env,webhcat-log4j,ranger-site,ranger-ugsync-site,ranger-admin-site,admin-properties,ranger-hive-policymgr-ssl,ranger-env,hcat-env,hive-site,ranger-hive-plugin-properties,webhcat-site,hive-exec-log4j,ams-log4j,webhcat-env,ams-ssl-server,hiveserver2-site,ams-hbase-log4j,hive-log4j,ams-ssl-client,ams-hbase-policy,ams-grafana-ini,ams-hbase-security-site,hive-env,ams-grafana-env,usersync-properties,ranger-hive-security
There are some issues reported related to the error that you are getting. Those errors usually occurs when we try to downgrade ambari.
Those issues are fixed in ambari 2.5 so i will suggest you to upgrade to ambari 2.5 instead of downgrading as it has many additional fixes including . The instructions for Ambari upgrade to 188.8.131.52 is available here: http://docs.hortonworks.com/HDPDocuments/Ambari-184.108.40.206/bk_ambari-upgrade/content/ambari_upgrade_gui...
 Downgrade Can Create Multiple Mappings For Latest Configs: https://issues.apache.org/jira/browse/AMBARI-19130
Thanks for your answer.
I thought about upgrade Ambari to 2.5, but how can I do it if my current ambari-server does not even start? So I can't accomplish prerequisites such as: