Add HTTP retry handling into task SDK api.client

task_sdk/pyproject.toml

@@ -30,6 +30,7 @@ dependencies = [
     "msgspec>=0.18.6",
     "psutil>=6.1.0",
     "structlog>=24.4.0",
+    "retryhttp>=1.2.0",
 ]
 classifiers = [
   "Framework :: Apache Airflow",

task_sdk/src/airflow/sdk/api/client.py

@@ -17,6 +17,8 @@
 
 from __future__ import annotations
 
+import logging
+import os
 import sys
 import uuid
 from http import HTTPStatus
@@ -26,6 +28,8 @@
 import msgspec
 import structlog
 from pydantic import BaseModel
+from retryhttp import retry, wait_retry_after
+from tenacity import before_log, wait_random_exponential
 from uuid6 import uuid7
 
 from airflow.sdk import __version__
@@ -263,6 +267,14 @@ def noop_handler(request: httpx.Request) -> httpx.Response:
     return httpx.Response(200, json={"text": "Hello, world!"})
 
 
+# Config options for SDK how retries on HTTP requests should be handled
+# Note: Given defaults make attempts after 1, 3, 7, 15, 31seconds, 1:03, 2:07, 3:37 and fails after 5:07min
+# As long as there is no other config facility in SDK we use ENV for the moment
+API_RETRIES = int(os.getenv("AIRFLOW__WORKERS__API_RETRIES", 10))
+API_RETRY_WAIT_MIN = int(os.getenv("AIRFLOW__WORKERS__API_RETRY_WAIT_MIN", 1))
+API_RETRY_WAIT_MAX = int(os.getenv("AIRFLOW__WORKERS__API_RETRY_WAIT_MAX", 90))
+
+
 class Client(httpx.Client):
     def __init__(self, *, base_url: str | None, dry_run: bool = False, token: str, **kwargs: Any):
         if (not base_url) ^ dry_run:
@@ -284,6 +296,21 @@ def __init__(self, *, base_url: str | None, dry_run: bool = False, token: str, *
             **kwargs,
         )
 
+    _default_wait = wait_random_exponential(min=API_RETRY_WAIT_MIN, max=API_RETRY_WAIT_MAX)
+
+    @retry(
+        reraise=True,
+        max_attempt_number=API_RETRIES,
+        wait_server_errors=_default_wait,
+        wait_network_errors=_default_wait,
+        wait_timeouts=_default_wait,
+        wait_rate_limited=wait_retry_after(fallback=_default_wait),  # No infinite timeout on HTTP 429
+        before_sleep=before_log(log, logging.WARNING),
+    )
+    def request(self, *args, **kwargs):
+        """Implement a convenience for httpx.Client.request with a retry layer."""
+        return super().request(*args, **kwargs)
+
     # We "group" or "namespace" operations by what they operate on, rather than a flat namespace with all
     # methods on one object prefixed with the object type (`.task_instances.update` rather than
     # `task_instance_update` etc.)

task_sdk/tests/api/test_client.py

@@ -18,6 +18,7 @@
 from __future__ import annotations
 
 import json
+from unittest import mock
 
 import httpx
 import pytest
@@ -30,18 +31,28 @@
 from airflow.utils.state import TerminalTIState
 
 
-class TestClient:
-    def test_error_parsing(self):
-        def handle_request(request: httpx.Request) -> httpx.Response:
-            """
-            A transport handle that always returns errors
-            """
+def make_client(transport: httpx.MockTransport) -> Client:
+    """Get a client with a custom transport"""
+    return Client(base_url="test://server", token="", transport=transport)
 
-            return httpx.Response(422, json={"detail": [{"loc": ["#0"], "msg": "err", "type": "required"}]})
 
-        client = Client(
-            base_url=None, dry_run=True, token="", mounts={"'http://": httpx.MockTransport(handle_request)}
-        )
+def make_client_w_responses(responses: list[httpx.Response]) -> Client:
+    """Helper fixture to create a mock client with custom responses."""
+
+    def handle_request(request: httpx.Request) -> httpx.Response:
+        return responses.pop(0)
+
+    return Client(
+        base_url=None, dry_run=True, token="", mounts={"'http://": httpx.MockTransport(handle_request)}
+    )
+
+
+class TestClient:
+    def test_error_parsing(self):
+        responses = [
+            httpx.Response(422, json={"detail": [{"loc": ["#0"], "msg": "err", "type": "required"}]})
+        ]
+        client = make_client_w_responses(responses)
 
         with pytest.raises(ServerResponseError) as err:
             client.get("http://error")
@@ -53,39 +64,92 @@ def handle_request(request: httpx.Request) -> httpx.Response:
         ]
 
     def test_error_parsing_plain_text(self):
-        def handle_request(request: httpx.Request) -> httpx.Response:
-            """
-            A transport handle that always returns errors
-            """
-
-            return httpx.Response(422, content=b"Internal Server Error")
-
-        client = Client(
-            base_url=None, dry_run=True, token="", mounts={"'http://": httpx.MockTransport(handle_request)}
-        )
+        responses = [httpx.Response(422, content=b"Internal Server Error")]
+        client = make_client_w_responses(responses)
 
         with pytest.raises(httpx.HTTPStatusError) as err:
             client.get("http://error")
         assert not isinstance(err.value, ServerResponseError)
 
     def test_error_parsing_other_json(self):
-        def handle_request(request: httpx.Request) -> httpx.Response:
-            # Some other json than an error body.
-            return httpx.Response(404, json={"detail": "Not found"})
-
-        client = Client(
-            base_url=None, dry_run=True, token="", mounts={"'http://": httpx.MockTransport(handle_request)}
-        )
+        responses = [httpx.Response(404, json={"detail": "Not found"})]
+        client = make_client_w_responses(responses)
 
         with pytest.raises(ServerResponseError) as err:
             client.get("http://error")
         assert err.value.args == ("Not found",)
         assert err.value.detail is None
 
+    @mock.patch("time.sleep", return_value=None)
+    def test_retry_handling_unrecoverable_error(self, mock_sleep):
+        responses: list[httpx.Response] = [
+            *[httpx.Response(500, text="Internal Server Error")] * 11,
+            httpx.Response(200, json={"detail": "Recovered from error - but will fail before"}),
+            httpx.Response(400, json={"detail": "Should not get here"}),
+        ]
+        client = make_client_w_responses(responses)
 
-def make_client(transport: httpx.MockTransport) -> Client:
-    """Get a client with a custom transport"""
-    return Client(base_url="test://server", token="", transport=transport)
+        with pytest.raises(httpx.HTTPStatusError) as err:
+            client.get("http://error")
+        assert not isinstance(err.value, ServerResponseError)
+        assert len(responses) == 3
+        assert mock_sleep.call_count == 9
+
+    @mock.patch("time.sleep", return_value=None)
+    def test_retry_handling_recovered(self, mock_sleep):
+        responses: list[httpx.Response] = [
+            *[httpx.Response(500, text="Internal Server Error")] * 3,
+            httpx.Response(200, json={"detail": "Recovered from error"}),
+            httpx.Response(400, json={"detail": "Should not get here"}),
+        ]
+        client = make_client_w_responses(responses)
+
+        response = client.get("http://error")
+        assert response.status_code == 200
+        assert len(responses) == 1
+        assert mock_sleep.call_count == 3
+
+    @mock.patch("time.sleep", return_value=None)
+    def test_retry_handling_overload(self, mock_sleep):
+        responses: list[httpx.Response] = [
+            httpx.Response(429, text="I am really busy atm, please back-off", headers={"Retry-After": "37"}),
+            httpx.Response(200, json={"detail": "Recovered from error"}),
+            httpx.Response(400, json={"detail": "Should not get here"}),
+        ]
+        client = make_client_w_responses(responses)
+
+        response = client.get("http://error")
+        assert response.status_code == 200
+        assert len(responses) == 1
+        assert mock_sleep.call_count == 1
+        assert mock_sleep.call_args[0][0] == 37
+
+    @mock.patch("time.sleep", return_value=None)
+    def test_retry_handling_non_retry_error(self, mock_sleep):
+        responses: list[httpx.Response] = [
+            httpx.Response(422, json={"detail": "Somehow this is a bad request"}),
+            httpx.Response(400, json={"detail": "Should not get here"}),
+        ]
+        client = make_client_w_responses(responses)
+
+        with pytest.raises(ServerResponseError) as err:
+            client.get("http://error")
+        assert len(responses) == 1
+        assert mock_sleep.call_count == 0
+        assert err.value.args == ("Somehow this is a bad request",)
+
+    @mock.patch("time.sleep", return_value=None)
+    def test_retry_handling_ok(self, mock_sleep):
+        responses: list[httpx.Response] = [
+            httpx.Response(200, json={"detail": "Recovered from error"}),
+            httpx.Response(400, json={"detail": "Should not get here"}),
+        ]
+        client = make_client_w_responses(responses)
+
+        response = client.get("http://error")
+        assert response.status_code == 200
+        assert len(responses) == 1
+        assert mock_sleep.call_count == 0
 
 
 class TestTaskInstanceOperations:

tests/cli/commands/remote_commands/test_task_command.py

@@ -496,6 +496,8 @@ def test_cli_run_no_local_no_raw_runs_executor(self, dag_maker):
                 mock.patch(
                     "airflow.executors.executor_loader.ExecutorLoader.get_default_executor"
                 ) as get_default_mock,
+                mock.patch("airflow.executors.local_executor.SimpleQueue"),  # Prevent a task being queued
+                mock.patch("airflow.executors.local_executor.LocalExecutor.end"),
             ):
                 EmptyOperator(task_id="task1")
                 EmptyOperator(task_id="task2", executor="foo_executor_alias")