Sometimes, attempting to run lambdas will return this type of error:
```
{"Type": "Server", "message": "Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists Traceback (most recent call last):\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_api.py\", line 338, in run_lambda\n 
event, context=context, version=version, asynchronous=asynchronous)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 81, in execute\n 
return do_execute()\n File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 70, in do_execute\n self._store_logs(func_details, log_output, invocation_time)\n 
File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 105, in _store_logs\n logs_client.create_log_group(logGroupName=log_group_name)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 357, in _api_call\n 
return self._make_api_call(operation_name, kwargs)\n 
File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 661, in _make_api_call\n 
raise error_class(parsed_response, operation_name)\n
botocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists\n", "__type": "InternalFailure"}
```
I am not yet sure if there are any particular settings that cause it, since it does not occur for certain deployments.

Will update if I can figure out the exact configuration.
from localstack.services.awslambda.lambda_api import BUCKET_MARKER_LOCAL
LOG = logging.getLogger(__name__)
CURRENTLY_UPDATING_RESOURCES = {}
RUN_SERVER_IN_PROCESS = False
MODEL_MAP = {
    'AWS::StepFunctions::Activity': service_models.StepFunctionsActivity
}
def start_cloudformation(port=None, asynchronous=False, update_listener=None):
    port = port or config.PORT_CLOUDFORMATION
    backend_port = DEFAULT_PORT_CLOUDFORMATION_BACKEND
    print('Starting mock CloudFormation (%s port %s)...' % (get_service_protocol(), port))
    start_proxy_for_service('cloudformation', port, backend_port, update_listener)
    if RUN_SERVER_IN_PROCESS:
        cmd = 'python "%s" cloudformation -p %s -H 0.0.0.0' % (__file__, backend_port)
        env_vars = {'PYTHONPATH': ':'.join(sys.path)}
        return do_run(cmd, asynchronous, env_vars=env_vars)
    else:
        argv = ['cloudformation', '-p', str(backend_port), '-H', '0.0.0.0']
        thread = FuncThread(start_up, argv)
        thread.start()
        return thread
def set_moto_account_ids(resource_json):
    def fix_ids(obj, **kwargs):
        if isinstance(obj, dict):
            for key, value in obj.items():
                if 'arn' in key.lower() and isinstance(value, six.string_types):
                    obj[key] = value.replace(TEST_AWS_ACCOUNT_ID, MOTO_ACCOUNT_ID)
        return obj
    return recurse_object(resource_json, fix_ids)
def get_entity_id(entity, resource_json=None):