Cache dynamodb client and resource in DynamoDB online store implement…

…ation (#2138)

Signed-off-by: Felix Wang <wangfelix98@gmail.com>

sdk/python/feast/infra/online_stores/dynamodb.py

@@ -58,6 +58,9 @@ class DynamoDBOnlineStore(OnlineStore):
     Online feature store for AWS DynamoDB.
     """
 
+    _dynamodb_client = None
+    _dynamodb_resource = None
+
     @log_exceptions_and_usage(online_store="dynamodb")
     def update(
         self,
@@ -70,7 +73,8 @@ def update(
     ):
         online_config = config.online_store
         assert isinstance(online_config, DynamoDBOnlineStoreConfig)
-        dynamodb_client, dynamodb_resource = _initialize_dynamodb(online_config.region)
+        dynamodb_client = self._get_dynamodb_client(online_config.region)
+        dynamodb_resource = self._get_dynamodb_resource(online_config.region)
 
         for table_instance in tables_to_keep:
             try:
@@ -105,7 +109,7 @@ def teardown(
     ):
         online_config = config.online_store
         assert isinstance(online_config, DynamoDBOnlineStoreConfig)
-        _, dynamodb_resource = _initialize_dynamodb(online_config.region)
+        dynamodb_resource = self._get_dynamodb_resource(online_config.region)
 
         for table in tables:
             _delete_table_idempotent(dynamodb_resource, table.name)
@@ -122,7 +126,7 @@ def online_write_batch(
     ) -> None:
         online_config = config.online_store
         assert isinstance(online_config, DynamoDBOnlineStoreConfig)
-        _, dynamodb_resource = _initialize_dynamodb(online_config.region)
+        dynamodb_resource = self._get_dynamodb_resource(online_config.region)
 
         table_instance = dynamodb_resource.Table(f"{config.project}.{table.name}")
         with table_instance.batch_writer() as batch:
@@ -151,7 +155,7 @@ def online_read(
     ) -> List[Tuple[Optional[datetime], Optional[Dict[str, ValueProto]]]]:
         online_config = config.online_store
         assert isinstance(online_config, DynamoDBOnlineStoreConfig)
-        _, dynamodb_resource = _initialize_dynamodb(online_config.region)
+        dynamodb_resource = self._get_dynamodb_resource(online_config.region)
 
         result: List[Tuple[Optional[datetime], Optional[Dict[str, ValueProto]]]] = []
         for entity_key in entity_keys:
@@ -172,12 +176,23 @@ def online_read(
                 result.append((None, None))
         return result
 
+    def _get_dynamodb_client(self, region: str):
+        if self._dynamodb_client is None:
+            self._dynamodb_client = _initialize_dynamodb_client(region)
+        return self._dynamodb_client
+
+    def _get_dynamodb_resource(self, region: str):
+        if self._dynamodb_resource is None:
+            self._dynamodb_resource = _initialize_dynamodb_resource(region)
+        return self._dynamodb_resource
+
+
+def _initialize_dynamodb_client(region: str):
+    return boto3.client("dynamodb", region_name=region)
+
 
-def _initialize_dynamodb(region: str):
-    return (
-        boto3.client("dynamodb", region_name=region),
-        boto3.resource("dynamodb", region_name=region),
-    )
+def _initialize_dynamodb_resource(region: str):
+    return boto3.resource("dynamodb", region_name=region)
 
 
 def _delete_table_idempotent(
@@ -231,7 +246,8 @@ def from_proto(infra_object_proto: InfraObjectProto) -> Any:
         )
 
     def update(self):
-        dynamodb_client, dynamodb_resource = _initialize_dynamodb(self.region)
+        dynamodb_client = _initialize_dynamodb_client(region=self.region)
+        dynamodb_resource = _initialize_dynamodb_resource(region=self.region)
 
         try:
             dynamodb_resource.create_table(
@@ -252,5 +268,5 @@ def update(self):
         dynamodb_client.get_waiter("table_exists").wait(TableName=f"{self.name}")
 
     def teardown(self):
-        _, dynamodb_resource = _initialize_dynamodb(self.region)
+        dynamodb_resource = _initialize_dynamodb_resource(region=self.region)
         _delete_table_idempotent(dynamodb_resource, self.name)