If you are using Phoenix, you must check if you have enabled namespace mapping.

HBase namespaces enable tighter control of where a particular data set is stored on the HBase RegionsServers. In Ambari’s HBase service, nore down if the following HBase configurations to see if you have mapped Phoenix schemas to the HBase namespaces.

HBase Config Value
phoenix.schema.isNamespaceMappingEnabled true
phoenix.schema.mapSystemTablesToNamespace true

If these two configurations are set to true, you must set them again using Cloudera Manager after you upgrade to Cloudera Manager.