diff --git a/python_modules/dagster/dagster/core/instance/__init__.py b/python_modules/dagster/dagster/core/instance/__init__.py
--- a/python_modules/dagster/dagster/core/instance/__init__.py
+++ b/python_modules/dagster/dagster/core/instance/__init__.py
@@ -1,39 +1,30 @@
-import datetime
 import logging
 import os
 import time
-from abc import ABCMeta
-from collections import defaultdict, namedtuple
+from collections import defaultdict
 from enum import Enum
-from typing import Optional
 
-import six
 import yaml
-from rx import Observable
 
 from dagster import check, seven
-from dagster.config import Field, Permissive
 from dagster.core.definitions.events import AssetKey
 from dagster.core.definitions.pipeline import PipelineDefinition, PipelineSubsetDefinition
 from dagster.core.errors import (
-    DagsterInvalidConfigError,
     DagsterInvariantViolationError,
     DagsterRunAlreadyExists,
     DagsterRunConflict,
 )
-from dagster.core.execution.resolve_versions import join_and_hash, resolve_step_output_versions
+from dagster.core.execution.resolve_versions import resolve_step_output_versions
 from dagster.core.storage.migration.utils import upgrading_instance
-from dagster.core.storage.pipeline_run import PipelineRun, PipelineRunStatus, PipelineRunsFilter
+from dagster.core.storage.pipeline_run import PipelineRun, PipelineRunStatus
 from dagster.core.storage.tags import MEMOIZED_RUN_TAG
 from dagster.core.system_config.objects import EnvironmentConfig
 from dagster.core.utils import str_format_list
-from dagster.serdes import ConfigurableClass, whitelist_for_serdes
+from dagster.serdes import ConfigurableClass
 from dagster.seven import get_current_datetime_in_utc
-from dagster.utils.merger import merge_dicts
-from dagster.utils.yaml_utils import load_yaml_from_globs
 
 from .config import DAGSTER_CONFIG_YAML_FILENAME
-from .ref import InstanceRef, compute_logs_directory
+from .ref import InstanceRef
 
 # 'airflow_execution_date' and 'is_airflow_ingest_pipeline' are hardcoded tags used in the
 # airflow ingestion logic (see: dagster_pipeline_factory.py). 'airflow_execution_date' stores the