nameError: caches is not defined

graphite: 1.1.2
Django==1.11.10

I add relay config to carbon.It's running on the same host.

configs:
PICKLE_RECEIVER_INTERFACE = 0.0.0.0
PICKLE_RECEIVER_PORT = 2004
CACHE_QUERY_INTERFACE = 127.0.0.1
RELAY_METHOD = consistent-hashing
DESTINATIONS = 127.0.0.1:2104:a, 127.0.0.1:2204:b

[cache]
LOCAL_DATA_DIR = /data/graphite/whisper/
LOG_DIR = /data/graphite/log/carbon/
MAX_CREATES_PER_MINUTE = 300

LOG_UPDATES = False
LOG_CACHE_HITS = False
LOG_CACHE_QUEUE_SORTS = False

CARBON_METRIC_PREFIX = stats.carbon
CARBON_METRIC_INTERVAL = 10

[cache:a]
LINE_RECEIVER_PORT = 2103
PICKLE_RECEIVER_PORT = 2104
CACHE_QUERY_PORT = 7102

[cache:b]
LINE_RECEIVER_PORT = 2203
PICKLE_RECEIVER_PORT = 2204
CACHE_QUERY_PORT = 7202

localsetting.py -relevant information

MEMCACHE_HOSTS = ['127.0.0.1:11211']
DEFAULT_CACHE_DURATION = 9

CARBONLINK_HOSTS = ['127.0.0.1:7102:a','127.0.0.1:7202:b']
CARBONLINK_TIMEOUT = 1.0

I am getting this error:
  File "/opt/graphite/bin/django-admin", line 11, in <module>
    sys.exit(execute_from_command_line())
  File "/opt/graphite/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/opt/graphite/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 308, in execute
    settings.INSTALLED_APPS
  File "/opt/graphite/local/lib/python2.7/site-packages/django/conf/__init__.py", line 56, in __getattr__
    self._setup(name)
  File "/opt/graphite/local/lib/python2.7/site-packages/django/conf/__init__.py", line 41, in _setup
    self._wrapped = Settings(settings_module)
  File "/opt/graphite/local/lib/python2.7/site-packages/django/conf/__init__.py", line 110, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/opt/graphite/webapp/graphite/settings.py", line 226, in <module>
    'TIMEOUT': DEFAULT_CACHE_DURATION,
NameError: name 'CACHES' is not defined

Where should be caches defined ? Should memcache define for both instances ?