fix: 🐛 fix the query to get the list of jobs in the queue

libs/libqueue/Makefile

@@ -2,8 +2,12 @@ include ../../tools/Common.mk
 
 .PHONY: test
 test:
-	MONGO_QUEUE_DATABASE="datasets_server_queue_test" poetry run python -m pytest -x tests
+	docker-compose -f tests/docker-compose.yml up -d --remove-orphans
+	MONGO_URL="mongodb://localhost:27020" MONGO_QUEUE_DATABASE="datasets_server_queue_test" poetry run python -m pytest -x tests
+	docker-compose -f tests/docker-compose.yml down
 
 .PHONY: coverage
 coverage:
-	MONGO_QUEUE_DATABASE="datasets_server_queue_test" poetry run python -m pytest -s --cov --cov-report xml:coverage.xml --cov-report=term tests
+	docker-compose -f tests/docker-compose.yml up -d --remove-orphans
+	MONGO_URL="mongodb://localhost:27020" MONGO_QUEUE_DATABASE="datasets_server_queue_test" poetry run python -m pytest -s --cov --cov-report xml:coverage.xml --cov-report=term tests
+	docker-compose -f tests/docker-compose.yml down

libs/libqueue/src/libqueue/queue.py

@@ -205,23 +205,28 @@ def get_finished(jobs: QuerySet[AnyJob]) -> QuerySet[AnyJob]:
     return jobs(status__nin=[Status.WAITING, Status.STARTED])
 
 
+def get_excluded_dataset_names(jobs: QuerySet[AnyJob], max_jobs_per_dataset: Optional[int] = None) -> List[str]:
+    if max_jobs_per_dataset is None:
+        return []
+    dataset_names = [job.dataset_name for job in jobs(status=Status.STARTED).only("dataset_name")]
+    return list(
+        {dataset_name for dataset_name in dataset_names if dataset_names.count(dataset_name) >= max_jobs_per_dataset}
+    )
+
+
 def start_job(jobs: QuerySet[AnyJob], max_jobs_per_dataset: Optional[int] = None) -> AnyJob:
-    waiting_jobs = get_waiting(jobs).order_by("+created_at").no_cache()
+    excluded_dataset_names = get_excluded_dataset_names(jobs, max_jobs_per_dataset)
+    next_waiting_job = (
+        jobs(status=Status.WAITING, dataset_name__nin=excluded_dataset_names)
+        .order_by("+created_at")
+        .no_cache()
+        .first()
+    )
     # ^ no_cache should generate a query on every iteration, which should solve concurrency issues between workers
-    for job in waiting_jobs:
-        if job.status is not Status.WAITING:
-            logger.warning(f"waiting job {job.to_id()} has a not the WAITING status. Ignoring it.")
-            continue
-        if job.started_at is not None:
-            logger.warning(f"waiting job {job.to_id()} has a non empty started_at field. Ignoring it.")
-            continue
-        if job.finished_at is not None:
-            logger.warning(f"waiting job {job.to_id()} has a non empty started_at field. Ignoring it.")
-            continue
-        if max_jobs_per_dataset is None or get_num_started_for_dataset(jobs, job.dataset_name) < max_jobs_per_dataset:
-            job.update(started_at=datetime.utcnow(), status=Status.STARTED)
-            return job
-    raise EmptyQueue(f"no job available (within the limit of {max_jobs_per_dataset} started jobs per dataset)")
+    if next_waiting_job is None:
+        raise EmptyQueue("no job available (within the limit of {max_jobs_per_dataset} started jobs per dataset)")
+    next_waiting_job.update(started_at=datetime.utcnow(), status=Status.STARTED)
+    return next_waiting_job
 
 
 def get_dataset_job(max_jobs_per_dataset: Optional[int] = None) -> Tuple[str, str]:

libs/libqueue/tests/docker-compose.yml

@@ -0,0 +1,10 @@
+version: "3.9"
+services:
+  mongodb-test-libqueue:
+    image: mongo
+    volumes:
+      - mongo-test-libqueue:/data/db:rw
+    ports:
+      - 27020:27017
+volumes:
+  mongo-test-libqueue:

libs/libqueue/tests/test_queue.py

@@ -8,6 +8,7 @@
     connect_to_queue,
     finish_dataset_job,
     get_dataset_job,
+    get_split_job,
     is_dataset_in_queue,
     is_split_in_queue,
 )
@@ -50,6 +51,24 @@ def test_add_job() -> None:
     finish_dataset_job(job_id, success=True)
 
 
+def test_max_jobs_per_dataset() -> None:
+    add_split_job("dataset", "config", "split1")
+    add_split_job("dataset", "config", "split2")
+    add_split_job("dataset", "config", "split3")
+    _, dataset_name, config_name, split_name = get_split_job()
+    assert dataset_name == "dataset"
+    assert config_name == "config"
+    assert split_name == "split1"
+    with pytest.raises(EmptyQueue):
+        get_split_job(0)
+    with pytest.raises(EmptyQueue):
+        get_split_job(1)
+    _, dataset_name, config_name, split_name = get_split_job(2)
+    assert split_name == "split2"
+    with pytest.raises(EmptyQueue):
+        get_split_job(2)
+
+
 def test_is_dataset_in_queue() -> None:
     dataset_name = "test_dataset"
     dataset_name_2 = "test_dataset_2"