fix(s3): cap parallel uploads behind proxy (ECO-410)

deepset_cloud_sdk/_s3/upload.py

@@ -266,23 +266,28 @@ async def upload_from_memory(
     ) -> S3UploadResult:
         """Upload content to the prefixed S3 namespace.
 
+        Uses the same concurrency limit as :meth:`upload_from_file` so bulk in-memory
+        uploads (including sidecar ``.meta.json`` objects) do not open unbounded
+        parallel connections—important behind corporate HTTP proxies.
+
         :param file_name: Name of the file.
         :param upload_session: UploadSession to associate the upload with.
         :param content: Content of the file.
         :param client_session: The aiohttp ClientSession to use for this request.
         :return: S3UploadResult object.
         """
-        try:
-            await self._upload_file_with_retries(file_name, upload_session, content, client_session)
-            return S3UploadResult(file_name=file_name, success=True)
-        except Exception as exception:  # pylint: disable=bare-except, disable=broad-exception-caught
-            logger.warning(
-                "Could not upload a file to deepset AI Platform",
-                file_name=file_name,
-                session_id=upload_session.session_id,
-                reason=str(exception),
-            )
-            return S3UploadResult(file_name=file_name, success=False, exception=exception)
+        async with self.semaphore:
+            try:
+                await self._upload_file_with_retries(file_name, upload_session, content, client_session)
+                return S3UploadResult(file_name=file_name, success=True)
+            except Exception as exception:  # pylint: disable=broad-exception-caught
+                logger.warning(
+                    "Could not upload a file to deepset AI Platform",
+                    file_name=file_name,
+                    session_id=upload_session.session_id,
+                    reason=str(exception),
+                )
+                return S3UploadResult(file_name=file_name, success=False, exception=exception)
 
     async def _process_results(
         self,

deepset_cloud_sdk/_service/files_service.py

@@ -39,10 +39,29 @@
 META_SUFFIX = ".meta.json"
 DIRECT_UPLOAD_THRESHOLD = 20
 DEFAULT_S3_CONCURRENCY = 10
+# Fewer parallel TLS connections through typical corporate proxies (avoids Windows
+# socket / semaphore exhaustion when many files upload at once; see ECO-410).
+PROXY_S3_CONCURRENCY = 4
 DEFAULT_MAX_ATTEMPTS = 5
 SAFE_MODE_CONCURRENCY = 1
 SAFE_MODE_MAX_ATTEMPTS = 10
 
+_PROXY_ENV_KEYS = ("HTTP_PROXY", "HTTPS_PROXY", "http_proxy", "https_proxy", "ALL_PROXY", "all_proxy")
+
+
+def _http_proxy_configured() -> bool:
+    """Return True when a proxy is set via common environment variables."""
+    return any(os.environ.get(key, "").strip() for key in _PROXY_ENV_KEYS)
+
+
+def _resolve_s3_concurrency(safe_mode: bool) -> int:
+    """Pick S3 client concurrency: safe mode, proxy-capped, or default."""
+    if safe_mode:
+        return SAFE_MODE_CONCURRENCY
+    if _http_proxy_configured():
+        return PROXY_S3_CONCURRENCY
+    return DEFAULT_S3_CONCURRENCY
+
 
 class FilesService:
     """Service for all file-related operations."""
@@ -69,8 +88,13 @@ async def factory(cls, config: CommonConfig) -> AsyncGenerator[FilesService, Non
         async with DeepsetCloudAPI.factory(config) as deepset_cloud_api:
             files_api = FilesAPI(deepset_cloud_api)
             upload_sessions_api = UploadSessionsAPI(deepset_cloud_api)
-            concurrency = SAFE_MODE_CONCURRENCY if config.safe_mode else DEFAULT_S3_CONCURRENCY
+            concurrency = _resolve_s3_concurrency(config.safe_mode)
             max_attempts = SAFE_MODE_MAX_ATTEMPTS if config.safe_mode else DEFAULT_MAX_ATTEMPTS
+            if not config.safe_mode and _http_proxy_configured():
+                logger.info(
+                    "HTTP(S) proxy detected: using reduced S3 upload concurrency.",
+                    concurrency=concurrency,
+                )
             async with S3(concurrency=concurrency, max_attempts=max_attempts) as s3:
                 yield cls(upload_sessions_api, files_api, s3)
 

tests/unit/service/test_files_service.py

@@ -28,7 +28,14 @@
     WriteMode,
 )
 from deepset_cloud_sdk._s3.upload import S3UploadResult, S3UploadSummary
-from deepset_cloud_sdk._service.files_service import FilesService
+from deepset_cloud_sdk._service.files_service import (
+    DEFAULT_S3_CONCURRENCY,
+    PROXY_S3_CONCURRENCY,
+    SAFE_MODE_CONCURRENCY,
+    FilesService,
+    _http_proxy_configured,
+    _resolve_s3_concurrency,
+)
 from deepset_cloud_sdk.models import DeepsetCloudFile, UserInfo
 
 
@@ -1117,3 +1124,36 @@ def test_directories_excluded_from_path_non_recursive(self) -> None:
         paths = [Path("tests/data/upload_folder_nested")]
         file_paths = FilesService._get_file_paths(paths=paths, recursive=False)
         assert file_paths == [Path("tests/data/upload_folder_nested/example.txt")]
+
+
+class TestResolveS3Concurrency:
+    @staticmethod
+    def _clear_proxy_env(monkeypatch: MonkeyPatch) -> None:
+        for key in (
+            "HTTP_PROXY",
+            "HTTPS_PROXY",
+            "http_proxy",
+            "https_proxy",
+            "ALL_PROXY",
+            "all_proxy",
+        ):
+            monkeypatch.delenv(key, raising=False)
+
+    def test_safe_mode_ignores_proxy(self, monkeypatch: MonkeyPatch) -> None:
+        self._clear_proxy_env(monkeypatch)
+        monkeypatch.setenv("HTTPS_PROXY", "http://proxy.example:8080")
+        assert _resolve_s3_concurrency(safe_mode=True) == SAFE_MODE_CONCURRENCY
+
+    def test_proxy_lowers_concurrency(self, monkeypatch: MonkeyPatch) -> None:
+        self._clear_proxy_env(monkeypatch)
+        monkeypatch.setenv("HTTPS_PROXY", "http://proxy.example:8080")
+        assert _resolve_s3_concurrency(safe_mode=False) == PROXY_S3_CONCURRENCY
+
+    def test_no_proxy_uses_default(self, monkeypatch: MonkeyPatch) -> None:
+        self._clear_proxy_env(monkeypatch)
+        assert _resolve_s3_concurrency(safe_mode=False) == DEFAULT_S3_CONCURRENCY
+
+    def test_http_proxy_configured_empty_string(self, monkeypatch: MonkeyPatch) -> None:
+        self._clear_proxy_env(monkeypatch)
+        monkeypatch.setenv("HTTP_PROXY", "   ")
+        assert _http_proxy_configured() is False