fix(agent): PENG-2457 defer sending data to the API in case there's no new data

jobbergate-agent/jobbergate_agent/jobbergate/update.py

@@ -184,6 +184,9 @@ async def update_job_metrics(active_job_submittion: ActiveJobSubmission) -> None
         results = await asyncio.gather(*list(tasks))
         data_points = chain.from_iterable(results)
         aggregated_data_points = aggregate_influx_measures(data_points)
+        if not aggregated_data_points:
+            # defer the API call since there's no data to be sent
+            return
         packed_data = msgpack.packb(aggregated_data_points)
 
         response = await jobbergate_api_client.put(

jobbergate-agent/tests/jobbergate/test_update.py

@@ -858,3 +858,60 @@ async def test_update_job_metrics__success_with_max_times_empty(
     mocked_chain.from_iterable.assert_called_once_with([dummy_data_points] * len(measurements))
     mocked_aggregate_influx_measures.assert_called_once_with(iter_dummy_data_points)
     mocked_msgpack.packb.assert_called_once_with("super-dummy-aggregated-data")
+
+
+@pytest.mark.asyncio
+@pytest.mark.usefixtures("mock_access_token")
+@pytest.mark.parametrize(
+    "job_submission_id, slurm_job_id, measurements",
+    [
+        (1, 22, [{"name": "measurement1"}, {"name": "measurement2"}]),
+        (2, 33, [{"name": "measurement1"}]),
+        (3, 11, [{"name": "measurement1"}, {"name": "measurement2"}, {"name": "measurement3"}]),
+    ],
+)
+@mock.patch("jobbergate_agent.jobbergate.update.fetch_influx_measurements")
+@mock.patch("jobbergate_agent.jobbergate.update.fetch_influx_data")
+@mock.patch("jobbergate_agent.jobbergate.update.aggregate_influx_measures")
+@mock.patch("jobbergate_agent.jobbergate.update.msgpack")
+@mock.patch("jobbergate_agent.jobbergate.update.chain")
+async def test_update_job_metrics__defer_api_call_upon_no_new_data(
+    mocked_chain: mock.MagicMock,
+    mocked_msgpack: mock.MagicMock,
+    mocked_aggregate_influx_measures: mock.MagicMock,
+    mocked_fetch_influx_data: mock.MagicMock,
+    mocked_fetch_influx_measurements: mock.MagicMock,
+    job_submission_id: int,
+    slurm_job_id: int,
+    measurements: list[dict[str, str]],
+    job_max_times_response: Callable[[int, int, int, int], dict[str, int | list[dict[str, int | str]]]],
+):
+    """
+    Test that the ``update_job_metrics()`` function will defer sending data to the API
+    when there's no new data to send.
+    """
+    active_job_submission = ActiveJobSubmission(id=job_submission_id, slurm_job_id=slurm_job_id)
+    job_max_times = job_max_times_response(job_submission_id, 0, 0, 0)
+
+    mocked_fetch_influx_measurements.return_value = measurements
+    mocked_fetch_influx_data.return_value = []
+    mocked_chain.from_iterable.return_value = []
+    mocked_aggregate_influx_measures.return_value = []
+
+    with respx.mock:
+        respx.get(f"{SETTINGS.BASE_API_URL}/jobbergate/job-submissions/agent/metrics/{job_submission_id}").mock(
+            return_value=httpx.Response(
+                status_code=200,
+                json=job_max_times,
+            )
+        )
+
+        await update_job_metrics(active_job_submission)
+
+    mocked_fetch_influx_measurements.assert_called_once_with()
+    mocked_fetch_influx_data.assert_has_calls(
+        [mock.call(slurm_job_id, measurement["name"]) for measurement in measurements]
+    )
+    mocked_chain.from_iterable.assert_called_once_with([[] for _ in range(len(measurements))])
+    mocked_aggregate_influx_measures.assert_called_once_with([])
+    mocked_msgpack.packb.assert_not_called()