Add back missing pool_pre_ping check (canada-ca#545)

* Add back missing pool_pre_ping check

* Add more checks

* increase max_overflow

Author: nsdeschenes

api/db.py

@@ -9,9 +9,13 @@
 DB_PORT = os.getenv("DB_PORT")
 DB_NAME = os.getenv("DB_NAME")
 
-# Add this in later branch -> pool_pre_ping=True,
 engine = create_engine(
     f"postgresql+psycopg2://{DB_USER}:{DB_PASS}@{DB_HOST}:{DB_PORT}/{DB_NAME}",
+    pool_size=10,
+    max_overflow=5,
+    pool_recycle=300,
+    pool_pre_ping=True,
+    pool_use_lifo=True,
 )
 
 db_session = scoped_session(