test: consumed bandwidth with large data dispersal

tests/networking_privacy/test_networking_privacy.py

@@ -1,7 +1,7 @@
 import pytest
 import psutil
 
-from src.libs.common import delay, to_app_id, to_index, generate_random_bytes
+from src.libs.common import delay, to_app_id, to_index, generate_random_bytes, generate_text_data
 from src.libs.custom_logger import get_custom_logger
 from src.steps.da import StepsDataAvailability
 from src.test_data import DATA_TO_DISPERSE
@@ -74,3 +74,36 @@ class TestNetworkingPrivacy(StepsDataAvailability):
         overhead = (consumed - data_sent) / data_sent
 
         assert overhead < 400, "Dispersal overhead is too high"
+
+    @pytest.mark.usefixtures("setup_4_node_cluster")
+    def test_consumed_bandwidth_large_data_dispersal(self):
+        net_io = psutil.net_io_counters()
+        prev_total = net_io.bytes_sent + net_io.bytes_recv
+
+        data_to_disperse = generate_text_data(2048)  # ~10kB
+
+        successful_dispersals = 0
+        for i in range(20):
+            try:
+                self.disperse_data(data_to_disperse, to_app_id(10), to_index(0))
+                successful_dispersals += 1
+            except Exception as ex:
+                logger.warning(f"Dispersal #{i} was not successful with error {ex}")
+
+            if successful_dispersals == 10:
+                break
+
+            delay(0.1)
+
+        net_io = psutil.net_io_counters()
+        curr_total = net_io.bytes_sent + net_io.bytes_recv
+
+        consumed = curr_total - prev_total
+
+        assert successful_dispersals == 10, "Unable to finish 10 successful dispersals"
+
+        data_sent = 2 * successful_dispersals * len(data_to_disperse)
+        overhead = (consumed - data_sent) / data_sent
+
+        # Large data should have less transfer overhead
+        assert overhead < 300, "Dispersal overhead is too high"