Expose history size and continue-as-new-suggested (#361)

temporalio/worker/_workflow_instance.py

@@ -175,6 +175,8 @@ def __init__(self, det: WorkflowInstanceDetails) -> None:
         self._time_ns = 0
         self._cancel_requested = False
         self._current_history_length = 0
+        self._current_history_size = 0
+        self._continue_as_new_suggested = False
         # Lazily loaded
         self._memo: Optional[Mapping[str, Any]] = None
         # Handles which are ready to run on the next event loop iteration
@@ -272,6 +274,8 @@ def activate(
         self._current_completion.successful.SetInParent()
         self._current_activation_error: Optional[Exception] = None
         self._current_history_length = act.history_length
+        self._current_history_size = act.history_size_bytes
+        self._continue_as_new_suggested = act.continue_as_new_suggested
         self._time_ns = act.timestamp.ToNanoseconds()
         self._is_replaying = act.is_replaying
 
@@ -738,6 +742,9 @@ def workflow_extern_functions(self) -> Mapping[str, Callable]:
     def workflow_get_current_history_length(self) -> int:
         return self._current_history_length
 
+    def workflow_get_current_history_size(self) -> int:
+        return self._current_history_size
+
     def workflow_get_external_workflow_handle(
         self, id: str, *, run_id: Optional[str]
     ) -> temporalio.workflow.ExternalWorkflowHandle[Any]:
@@ -760,6 +767,9 @@ def workflow_get_signal_handler(self, name: Optional[str]) -> Optional[Callable]
     def workflow_info(self) -> temporalio.workflow.Info:
         return self._outbound.info()
 
+    def workflow_is_continue_as_new_suggested(self) -> bool:
+        return self._continue_as_new_suggested
+
     def workflow_is_replaying(self) -> bool:
         return self._is_replaying
 

temporalio/workflow.py

@@ -336,11 +336,34 @@ def _logger_details(self) -> Mapping[str, Any]:
     def get_current_history_length(self) -> int:
         """Get the current number of events in history.
 
+        Note, this value may not be up to date if accessed inside a query.
+
         Returns:
             Current number of events in history (up until the current task).
         """
         return _Runtime.current().workflow_get_current_history_length()
 
+    def get_current_history_size(self) -> int:
+        """Get the current byte size of history.
+
+        Note, this value may not be up to date if accessed inside a query.
+
+        Returns:
+            Current byte-size of history (up until the current task).
+        """
+        return _Runtime.current().workflow_get_current_history_size()
+
+    def is_continue_as_new_suggested(self) -> bool:
+        """Get whether or not continue as new is suggested.
+
+        Note, this value may not be up to date if accessed inside a query.
+
+        Returns:
+            True if the server is configured to suggest continue as new and it
+            is suggested.
+        """
+        return _Runtime.current().workflow_is_continue_as_new_suggested()
+
 
 @dataclass(frozen=True)
 class ParentInfo:
@@ -405,6 +428,10 @@ def workflow_extern_functions(self) -> Mapping[str, Callable]:
     def workflow_get_current_history_length(self) -> int:
         ...
 
+    @abstractmethod
+    def workflow_get_current_history_size(self) -> int:
+        ...
+
     @abstractmethod
     def workflow_get_external_workflow_handle(
         self, id: str, *, run_id: Optional[str]
@@ -423,6 +450,10 @@ def workflow_get_signal_handler(self, name: Optional[str]) -> Optional[Callable]
     def workflow_info(self) -> Info:
         ...
 
+    @abstractmethod
+    def workflow_is_continue_as_new_suggested(self) -> bool:
+        ...
+
     @abstractmethod
     def workflow_is_replaying(self) -> bool:
         ...

tests/conftest.py

@@ -79,6 +79,8 @@ async def env(env_type: str) -> AsyncGenerator[WorkflowEnvironment, None]:
             dev_server_extra_args=[
                 "--dynamic-config-value",
                 "system.forceSearchAttributesCacheRefreshOnRead=true",
+                "--dynamic-config-value",
+                f"limit.historyCount.suggestContinueAsNew={CONTINUE_AS_NEW_SUGGEST_HISTORY_COUNT}",
             ]
         )
     elif env_type == "time-skipping":
@@ -101,3 +103,11 @@ async def worker(
     worker = ExternalPythonWorker(env)
     yield worker
     await worker.close()
+
+
+CONTINUE_AS_NEW_SUGGEST_HISTORY_COUNT = 50
+
+
+@pytest.fixture
+def continue_as_new_suggest_history_count() -> int:
+    return CONTINUE_AS_NEW_SUGGEST_HISTORY_COUNT

tests/worker/test_workflow.py

@@ -132,7 +132,6 @@ class InfoWorkflow:
     async def run(self) -> Dict:
         # Convert to JSON and back so it'll stringify un-JSON-able pieces
         ret = dataclasses.asdict(workflow.info())
-        ret["current_history_length"] = workflow.info().get_current_history_length()
         return json.loads(json.dumps(ret, default=str))
 
 
@@ -158,7 +157,6 @@ async def test_workflow_info(client: Client, env: WorkflowEnvironment):
         )
         assert info["attempt"] == 1
         assert info["cron_schedule"] is None
-        assert info["current_history_length"] == 3
         assert info["execution_timeout"] is None
         assert info["namespace"] == client.namespace
         assert info["retry_policy"] == json.loads(
@@ -173,6 +171,68 @@ async def test_workflow_info(client: Client, env: WorkflowEnvironment):
         assert info["workflow_type"] == "InfoWorkflow"
 
 
+@dataclass
+class HistoryInfo:
+    history_length: int
+    history_size: int
+    continue_as_new_suggested: bool
+
+
+@workflow.defn
+class HistoryInfoWorkflow:
+    @workflow.run
+    async def run(self) -> None:
+        # Just wait forever
+        await workflow.wait_condition(lambda: False)
+
+    @workflow.signal
+    async def bunch_of_events(self, count: int) -> None:
+        # Create a lot of one-day timers
+        for _ in range(count):
+            asyncio.create_task(asyncio.sleep(60 * 60 * 24))
+
+    @workflow.query
+    def get_history_info(self) -> HistoryInfo:
+        return HistoryInfo(
+            history_length=workflow.info().get_current_history_length(),
+            history_size=workflow.info().get_current_history_size(),
+            continue_as_new_suggested=workflow.info().is_continue_as_new_suggested(),
+        )
+
+
+async def test_workflow_history_info(
+    client: Client, env: WorkflowEnvironment, continue_as_new_suggest_history_count: int
+):
+    if env.supports_time_skipping:
+        pytest.skip("Java test server does not support should continue as new")
+    async with new_worker(client, HistoryInfoWorkflow) as worker:
+        handle = await client.start_workflow(
+            HistoryInfoWorkflow.run,
+            id=f"workflow-{uuid.uuid4()}",
+            task_queue=worker.task_queue,
+        )
+        # Issue query before anything else, which should mean only a history
+        # size of 3, at least 100 bytes of history, and no continue as new
+        # suggestion
+        orig_info = await handle.query(HistoryInfoWorkflow.get_history_info)
+        assert orig_info.history_length == 3
+        assert orig_info.history_size > 100
+        assert not orig_info.continue_as_new_suggested
+
+        # Now send a lot of events
+        await handle.signal(
+            HistoryInfoWorkflow.bunch_of_events, continue_as_new_suggest_history_count
+        )
+        # Send one more event to trigger the WFT update. We have to do this
+        # because just a query will have a stale representation of history
+        # counts, but signal forces a new WFT.
+        await handle.signal(HistoryInfoWorkflow.bunch_of_events, 1)
+        new_info = await handle.query(HistoryInfoWorkflow.get_history_info)
+        assert new_info.history_length > continue_as_new_suggest_history_count
+        assert new_info.history_size > orig_info.history_size
+        assert new_info.continue_as_new_suggested
+
+
 @workflow.defn
 class SignalAndQueryWorkflow:
     def __init__(self) -> None: