Starting CloudForms Management engine produces the error "`server_for_key': No server available (Dalli::RingError)"

Issue

• When starting CloudForms Management Engine, an error appears reporting "server_for_key: No server available (Dalli::RingError)`.
• Loading the rails console produces a similar error:

# vmdb
# bundle exec rails console
/opt/rh/cfme-gemset/gems/dalli-2.7.6/lib/dalli/ring.rb:45:in `server_for_key': No server available (Dalli::RingError)
        from /opt/rh/cfme-gemset/gems/dalli-2.7.6/lib/dalli/client.rb:236:in `alive!'
        from /opt/rh/cfme-gemset/gems/dalli-2.7.6/lib/rack/session/dalli.rb:19:in `initialize'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/session/abstract_store.rb:32:in `initialize'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/session/mem_cache_store.rb:22:in `initialize'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:35:in `new'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:35:in `build'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:100:in `block in build'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:100:in `each'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:100:in `inject'
        from /opt/rh/cfme-gemset/gems/actionpack-5.0.3/lib/action_dispatch/middleware/stack.rb:100:in `build'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:508:in `block in app'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:504:in `synchronize'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/engine.rb:504:in `app'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/application/finisher.rb:37:in `block in '
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:30:in `instance_exec'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:30:in `run'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:55:in `block in run_initializers'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:228:in `block in tsort_each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:431:in `each_strongly_connected_component_from'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:349:in `block in each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `call'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:347:in `each_strongly_connected_component'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:226:in `tsort_each'
        from /opt/rh/rh-ruby23/root/usr/share/ruby/tsort.rb:205:in `tsort_each'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/initializable.rb:54:in `run_initializers'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/application.rb:352:in `initialize!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/railtie.rb:193:in `public_send'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/railtie.rb:193:in `method_missing'
        from /var/www/miq/vmdb/config/environment.rb:5:in `'
        from /opt/rh/cfme-gemset/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:293:in `require'
        from /opt/rh/cfme-gemset/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:293:in `block in require'
        from /opt/rh/cfme-gemset/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:259:in `load_dependency'
        from /opt/rh/cfme-gemset/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:293:in `require'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/application.rb:328:in `require_environment!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:157:in `require_application_and_environment!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:77:in `console'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
        from /opt/rh/cfme-gemset/gems/railties-5.0.3/lib/rails/commands.rb:18:in `'
        from bin/rails:4:in `require'