Warn if concurrent_batches config is set to True, but the available adapter doesn't support it

.changes/unreleased/Fixes-20241212-113611.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: Warn about invalid usages of `concurrent_batches` config
+time: 2024-12-12T11:36:11.451962-06:00
+custom:
+  Author: QMalcolm
+  Issue: "11122"

core/dbt/events/core_types.proto

@@ -928,6 +928,18 @@ message MicrobatchModelNoEventTimeInputsMsg {
 }
 
 
+// I075
+message InvalidConcurrentBatchesConfig {
+    int32 num_models = 1;
+    string adapter_type = 2;
+}
+
+message InvalidConcurrentBatchesConfigMsg {
+    CoreEventInfo info = 1;
+    InvalidConcurrentBatchesConfig data = 2;
+}
+
+
 // M - Deps generation
 
 

core/dbt/events/types.py

@@ -967,6 +967,16 @@ def message(self) -> str:
         return warning_tag(msg)
 
 
+class InvalidConcurrentBatchesConfig(WarnLevel):
+    def code(self) -> str:
+        return "I075"
+
+    def message(self) -> str:
+        maybe_plural_count_of_models = pluralize(self.num_models, "microbatch model")
+        description = f"Found {maybe_plural_count_of_models} with the `concurrent_batches` config set to true, but the {self.adapter_type} adapter does not support running batches concurrently. Batches will be run sequentially."
+        return line_wrap_message(warning_tag(description))
+
+
 # =======================================================
 # M - Deps generation
 # =======================================================

core/dbt/parser/manifest.py

@@ -17,6 +17,7 @@
 import dbt.utils
 import dbt_common.utils
 from dbt import plugins
+from dbt.adapters.capability import Capability
 from dbt.adapters.factory import (
     get_adapter,
     get_adapter_package_names,
@@ -66,6 +67,7 @@
     ArtifactWritten,
     DeprecatedModel,
     DeprecatedReference,
+    InvalidConcurrentBatchesConfig,
     InvalidDisabledTargetInTestNode,
     MicrobatchModelNoEventTimeInputs,
     NodeNotFoundOrDisabled,
@@ -510,6 +512,7 @@
         self.check_for_model_deprecations()
         self.check_for_spaces_in_resource_names()
         self.check_for_microbatch_deprecations()
+        self.check_forcing_batch_concurrency()
 
         return self.manifest
 
@@ -1484,6 +1487,27 @@
                     if not has_input_with_event_time_config:
                         fire_event(MicrobatchModelNoEventTimeInputs(model_name=node.name))
 
+    def check_forcing_batch_concurrency(self) -> None:
+        if self.manifest.use_microbatch_batches(project_name=self.root_project.project_name):
+            adapter = get_adapter(self.root_project)
+
+            if not adapter.supports(Capability.MicrobatchConcurrency):
+                models_forcing_concurrent_batches = 0
+                for node in self.manifest.nodes.values():
+                    if (
+                        hasattr(node.config, "concurrent_batches")
+                        and node.config.concurrent_batches is True
+                    ):
+                        models_forcing_concurrent_batches += 1
+
+                if models_forcing_concurrent_batches > 0:
+                    warn_or_error(
+                        InvalidConcurrentBatchesConfig(
+                            num_models=models_forcing_concurrent_batches,
+                            adapter_type=adapter.type(),
+                        )
+                    )
+
     def write_perf_info(self, target_path: str):
         path = os.path.join(target_path, PERF_INFO_FILE_NAME)
         write_file(path, json.dumps(self._perf_info, cls=dbt.utils.JSONEncoder, indent=4))

tests/functional/microbatch/test_microbatch.py

@@ -7,6 +7,7 @@
     ArtifactWritten,
     EndOfRunSummary,
     GenericExceptionOnRun,
+    InvalidConcurrentBatchesConfig,
     JinjaLogDebug,
     LogBatchResult,
     LogModelResult,
@@ -71,6 +72,11 @@
 select * from {{ ref('input_model') }}
 """
 
+microbatch_model_force_concurrent_batches_sql = """
+{{ config(materialized='incremental', incremental_strategy='microbatch', unique_key='id', event_time='event_time', batch_size='day', begin=modules.datetime.datetime(2020, 1, 1, 0, 0, 0), concurrent_batches=true) }}
+select * from {{ ref('input_model') }}
+"""
+
 microbatch_yearly_model_sql = """
 {{ config(materialized='incremental', incremental_strategy='microbatch', unique_key='id', event_time='event_time', batch_size='year', begin=modules.datetime.datetime(2020, 1, 1, 0, 0, 0)) }}
 select * from {{ ref('input_model') }}
@@ -1083,3 +1089,42 @@ def test_microbatch(
 
         # we had a bug where having only one batch caused a generic exception
         assert len(generic_exception_catcher.caught_events) == 0
+
+
+class TestCanSilenceInvalidConcurrentBatchesConfigWarning(BaseMicrobatchTest):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "input_model.sql": input_model_sql,
+            "microbatch_model.sql": microbatch_model_force_concurrent_batches_sql,
+        }
+
+    @pytest.fixture
+    def event_catcher(self) -> EventCatcher:
+        return EventCatcher(event_to_catch=InvalidConcurrentBatchesConfig)  # type: ignore
+
+    def test_microbatch(
+        self,
+        project,
+        event_catcher: EventCatcher,
+    ) -> None:
+        # This test works because postgres doesn't support concurrent batch execution
+        # If the postgres adapter starts supporting concurrent batch execution we'll
+        # need to start mocking the return value of `adapter.supports()`
+
+        with patch_microbatch_end_time("2020-01-01 13:57:00"):
+            _ = run_dbt(["run"], callbacks=[event_catcher.catch])
+        # We didn't silence the warning, so we get it
+        assert len(event_catcher.caught_events) == 1
+
+        # Clear caught events
+        event_catcher.caught_events = []
+
+        # Run again with silencing
+        with patch_microbatch_end_time("2020-01-01 13:57:00"):
+            _ = run_dbt(
+                ["run", "--warn-error-options", "{'silence': ['InvalidConcurrentBatchesConfig']}"],
+                callbacks=[event_catcher.catch],
+            )
+        # Because we silenced the warning, it shouldn't get fired
+        assert len(event_catcher.caught_events) == 0

tests/unit/parser/test_manifest.py

@@ -1,18 +1,21 @@
 from argparse import Namespace
+from typing import Optional
 from unittest.mock import MagicMock, patch
 
 import pytest
 from pytest_mock import MockerFixture
 
+from dbt.adapters.postgres import PostgresAdapter
 from dbt.artifacts.resources.base import FileHash
 from dbt.config import RuntimeConfig
 from dbt.contracts.graph.manifest import Manifest, ManifestStateCheck
-from dbt.events.types import UnusedResourceConfigPath
+from dbt.events.types import InvalidConcurrentBatchesConfig, UnusedResourceConfigPath
 from dbt.flags import set_from_args
 from dbt.parser.manifest import ManifestLoader, _warn_for_unused_resource_config_paths
 from dbt.parser.read_files import FileDiff
 from dbt.tracking import User
 from dbt_common.events.event_manager_client import add_callback_to_manager
+from tests.unit.fixtures import model_node
 from tests.utils import EventCatcher
 
 
@@ -238,3 +241,58 @@ def test_warn_for_unused_resource_config_paths(
         else:
             assert len(catcher.caught_events) == 1
             assert f"{resource_type}.{path}" in str(catcher.caught_events[0].data)
+
+
+class TestCheckForcingConcurrentBatches:
+    @pytest.fixture
+    @patch("dbt.parser.manifest.ManifestLoader.build_manifest_state_check")
+    @patch("dbt.parser.manifest.os.path.exists")
+    @patch("dbt.parser.manifest.open")
+    def manifest_loader(
+        self, patched_open, patched_os_exist, patched_state_check
+    ) -> ManifestLoader:
+        mock_project = MagicMock(RuntimeConfig)
+        mock_project.project_target_path = "mock_target_path"
+        mock_project.project_name = "mock_project_name"
+        return ManifestLoader(mock_project, {})
+
+    @pytest.fixture
+    def event_catcher(self) -> EventCatcher:
+        return EventCatcher(InvalidConcurrentBatchesConfig)  # type: ignore
+
+    @pytest.mark.parametrize(
+        "adapter_support,concurrent_batches_config,expect_warning",
+        [
+            (False, True, True),
+            (False, False, False),
+            (False, None, False),
+            (True, True, False),
+            (True, False, False),
+            (True, None, False),
+        ],
+    )
+    def test_check_forcing_concurrent_batches(
+        self,
+        mocker: MockerFixture,
+        manifest_loader: ManifestLoader,
+        postgres_adapter: PostgresAdapter,
+        event_catcher: EventCatcher,
+        adapter_support: bool,
+        concurrent_batches_config: Optional[bool],
+        expect_warning: bool,
+    ):
+        add_callback_to_manager(event_catcher.catch)
+        model = model_node()
+        model.config.concurrent_batches = concurrent_batches_config
+        mocker.patch.object(postgres_adapter, "supports").return_value = adapter_support
+        mocker.patch("dbt.parser.manifest.get_adapter").return_value = postgres_adapter
+        mocker.patch.object(manifest_loader.manifest, "use_microbatch_batches").return_value = True
+
+        manifest_loader.manifest.add_node_nofile(model)
+        manifest_loader.check_forcing_batch_concurrency()
+
+        if expect_warning:
+            assert len(event_catcher.caught_events) == 1
+            assert "Batches will be run sequentially" in event_catcher.caught_events[0].info.msg  # type: ignore
+        else:
+            assert len(event_catcher.caught_events) == 0

tests/unit/test_events.py

@@ -289,6 +289,7 @@ def test_event_codes(self):
     core_types.FreshnessConfigProblem(msg=""),
     core_types.SemanticValidationFailure(msg=""),
     core_types.MicrobatchModelNoEventTimeInputs(model_name=""),
+    core_types.InvalidConcurrentBatchesConfig(num_models=1, adapter_type=""),
     # M - Deps generation ======================
     core_types.GitSparseCheckoutSubdirectory(subdir=""),
     core_types.GitProgressCheckoutRevision(revision=""),