define constants.DEFAULT_DB_DRYRUN_URL and fix StaticPool conditions

freqtrade/arguments.py

@@ -108,7 +108,7 @@ class Arguments(object):
             help='Override trades database URL, this is useful if dry_run is enabled'
                  ' or in custom deployments (default: %(default)s)',
             dest='db_url',
-            default=constants.DEFAULT_DB_URL,
+            default=constants.DEFAULT_DB_PROD_URL,
             type=str,
             metavar='PATH',
         )

freqtrade/configuration.py

@@ -103,12 +103,12 @@ class Configuration(object):
 
         if config.get('dry_run', False):
             logger.info('Dry run is enabled')
-            if config.get('db_url') in [None, constants.DEFAULT_DB_URL]:
+            if config.get('db_url') in [None, constants.DEFAULT_DB_PROD_URL]:
                 # Default to in-memory db for dry_run if not specified
-                config['db_url'] = 'sqlite://'
+                config['db_url'] = constants.DEFAULT_DB_DRYRUN_URL
         else:
             if not config.get('db_url', None):
-                config['db_url'] = constants.DEFAULT_DB_URL
+                config['db_url'] = constants.DEFAULT_DB_PROD_URL
             logger.info('Dry run is disabled')
 
         logger.info('Using DB: "{}"'.format(config['db_url']))

freqtrade/constants.py

@@ -9,7 +9,8 @@ TICKER_INTERVAL = 5  # min
 HYPEROPT_EPOCH = 100  # epochs
 RETRY_TIMEOUT = 30  # sec
 DEFAULT_STRATEGY = 'DefaultStrategy'
-DEFAULT_DB_URL = 'sqlite:///tradesv3.sqlite'
+DEFAULT_DB_PROD_URL = 'sqlite:///tradesv3.sqlite'
+DEFAULT_DB_DRYRUN_URL = 'sqlite://'
 
 TICKER_INTERVAL_MINUTES = {
     '1m': 1,

freqtrade/persistence.py

@@ -16,6 +16,8 @@ from sqlalchemy.orm.scoping import scoped_session
 from sqlalchemy.orm.session import sessionmaker
 from sqlalchemy.pool import StaticPool
 
+from freqtrade import constants
+
 logger = logging.getLogger(__name__)
 
 _CONF = {}
@@ -35,10 +37,8 @@ def init(config: Dict) -> None:
     db_url = _CONF.get('db_url', None)
     kwargs = {}
 
-    if not db_url and _CONF.get('dry_run', False):
-        # Default to in-memory db if not specified
-        # and take care of thread ownership if in-memory db
-        db_url = 'sqlite://'
+    if db_url == constants.DEFAULT_DB_DRYRUN_URL:
+        # Take care of thread ownership if in-memory db
         kwargs.update({
             'connect_args': {'check_same_thread': False},
             'poolclass': StaticPool,
@@ -53,7 +53,7 @@ def init(config: Dict) -> None:
     check_migrate(engine)
 
     # Clean dry_run DB
-    if _CONF.get('dry_run', False) and db_url != 'sqlite://':
+    if _CONF.get('dry_run', False) and db_url != constants.DEFAULT_DB_DRYRUN_URL:
         clean_dry_run_db()