2 files changed, 10 insertions, 5 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 99934a0e31..c8d5f679a8 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -1006,7 +1006,16 @@ module ActiveRecord
       # for (not necessarily the current class).
       def retrieve_connection(spec_name) #:nodoc:
         pool = retrieve_connection_pool(spec_name)
-        raise ConnectionNotEstablished, "No connection pool with '#{spec_name}' found." unless pool
+
+        unless pool
+          # multiple database application
+          if ActiveRecord::Base.connection_handler != ActiveRecord::Base.default_connection_handler
+            raise ConnectionNotEstablished, "No connection pool with '#{spec_name}' found for the '#{ActiveRecord::Base.current_role}' role."
+          else
+            raise ConnectionNotEstablished, "No connection pool with '#{spec_name}' found."
+          end
+        end
+
         pool.connection
       end
 
diff --git a/activerecord/lib/active_record/connection_handling.rb b/activerecord/lib/active_record/connection_handling.rb
index 4a941055d1..558cdeccf2 100644
--- a/activerecord/lib/active_record/connection_handling.rb
+++ b/activerecord/lib/active_record/connection_handling.rb
@@ -158,10 +158,6 @@ module ActiveRecord
     end
 
     def with_handler(handler_key, &blk) # :nodoc:
-      unless ActiveRecord::Base.connection_handlers.keys.include?(handler_key)
-        raise ArgumentError, "The #{handler_key} role does not exist. Add it by establishing a connection with `connects_to` or use an existing role (#{ActiveRecord::Base.connection_handlers.keys.join(", ")})."
-      end
-
       handler = lookup_connection_handler(handler_key)
       swap_connection_handler(handler, &blk)
     end