update comment

Author: paulineribeyre

gen3workflow/app.py

@@ -66,8 +66,16 @@ async def get_status():
         root_path=config["DOCS_URL_PREFIX"],
         generate_unique_id_function=generate_unique_route_id,
     )
-    # TODO check ideal timeout for AWS calls
-    app.async_client = httpx_client or httpx.AsyncClient(timeout=300)
+
+    # `async_client` is used to hit the TES API, the Arborist service and AWS S3.
+    # Calls to S3 tend to timeout when uploading large files (and we might also be rate-limited).
+    # AsyncHTTPTransport supports retrying on httpx.ConnectError or httpx.ConnectTimeout.
+    # The `httpx_client` parameter is not meant to be used in production. It allows mocking
+    # external calls when testing.
+    app.async_client = httpx_client or httpx.AsyncClient(
+        transport=httpx.AsyncHTTPTransport(retries=3), timeout=120
+    )
+
     app.include_router(ga4gh_tes_router, tags=["GA4GH TES"])
     app.include_router(s3_router, tags=["S3"])
     app.include_router(storage_router, tags=["Storage"])

tests/conftest.py

@@ -349,7 +349,7 @@ async def handle_request(request: Request):
             httpx_client_function = getattr(httpx.AsyncClient(), request.method.lower())
             return await httpx_client_function(url)
 
-    # set the httpx clients used by the app and by the Arborist client to mock clients that
+    # the httpx clients used by the app and by gen3authz are set to mock clients that
     # call `handle_request`
     mock_httpx_client = httpx.AsyncClient(transport=httpx.MockTransport(handle_request))
     app = get_app(httpx_client=mock_httpx_client)