Raise an exception if any indexer workers fail their health check (#3726

)

* Raise an exception if any indexer workers fail their health check

* Add tests for failure case

* Add tests for happy path

* Simplify pook assertions

Co-authored-by: sarayourfriend <[email protected]>

* Reword comment to be more accurate

---------

Co-authored-by: sarayourfriend <[email protected]>

ingestion_server/ingestion_server/distributed_reindex_scheduler.py

@@ -50,11 +50,17 @@ def _assign_work(db_conn, workers, model_name, table_name, target_index):
 
     worker_url_template = "http://{}:8002"
     # Wait for the workers to start.
+    failures = []
     for worker in workers:
         worker_url = worker_url_template.format(worker)
         succeeded = _wait_for_healthcheck(f"{worker_url}/healthcheck")
         if not succeeded:
-            return False
+            failures.append(worker)
+    if failures:
+        raise ValueError(
+            f"Some workers didn't respond to health check: {','.join(failures)}"
+        )
+
     for idx, worker in enumerate(workers):
         worker_url = worker_url_template.format(worker)
         params = {

ingestion_server/test/unit_tests/test_distributed_reindex_scheduler.py

@@ -0,0 +1,83 @@
+from unittest import mock
+
+import pook
+import pytest
+
+from ingestion_server import distributed_reindex_scheduler
+
+
+@pytest.mark.parametrize(
+    "estimated_records, record_limit, workers, expected_ranges",
+    [
+        # One worker
+        (100, 1000, ["worker1"], [(0, 100)]),
+        # Multiple workers, even split
+        (100, 1000, ["worker1", "worker2"], [(0, 50), (50, 100)]),
+        # Multiple workers, uneven split
+        # NOTE: records get dropped in this case
+        (100, 1000, ["worker1", "worker2", "worker3"], [(0, 33), (33, 66), (66, 99)]),
+        # One worker, limited
+        (100, 55, ["worker1"], [(0, 55)]),
+        # Two workers, limited
+        (100, 50, ["worker1", "worker2"], [(0, 25), (25, 50)]),
+    ],
+)
+def test_assign_work(estimated_records, record_limit, workers, expected_ranges):
+    # Checks for the parameters
+    assert len(workers) == len(
+        expected_ranges
+    ), "Number of workers and expected ranges do not match, correct the test parameters"
+    # Set up database mock response
+    mock_db = mock.MagicMock()
+    mock_db.cursor.return_value.__enter__.return_value.fetchone.return_value = [
+        estimated_records
+    ]
+    # Enable pook & mock other internal functions
+    with pook.use(), mock.patch(
+        "ingestion_server.distributed_reindex_scheduler.get_record_limit"
+    ) as mock_get_record_limit, mock.patch(
+        "ingestion_server.distributed_reindex_scheduler._wait_for_healthcheck"
+    ) as mock_wait_for_healthcheck:
+        mock_wait_for_healthcheck.return_value = True
+        mock_get_record_limit.return_value = record_limit
+
+        # Set up pook matches
+        for worker, (start_id, end_id) in zip(workers, expected_ranges):
+            pook.post(f"http://{worker}:8002/indexing_task").json(
+                {
+                    "model_name": "sample_model",
+                    "table_name": "sample_table",
+                    "target_index": "sample_index",
+                    "start_id": start_id,
+                    "end_id": end_id,
+                }
+            )
+
+        distributed_reindex_scheduler._assign_work(
+            mock_db,
+            workers,
+            "sample_model",
+            "sample_table",
+            "sample_index",
+        )
+
+        # Raise an exception to ensure all pook requests were matched
+        assert pook.isdone()
+
+
+def test_assign_work_workers_fail():
+    mock_db = mock.MagicMock()
+    mock_db.cursor.return_value.__enter__.return_value.fetchone.return_value = [100]
+    with mock.patch(
+        "ingestion_server.distributed_reindex_scheduler._wait_for_healthcheck"
+    ) as mock_wait_for_healthcheck, pook.use(False):
+        mock_wait_for_healthcheck.return_value = False
+
+        with pytest.raises(ValueError, match="Some workers didn't respond"):
+            distributed_reindex_scheduler._assign_work(
+                mock_db,
+                ["worker"] * 6,
+                "fake-model",
+                "fake-table",
+                "target-index",
+            )