Hermes-agent

gateway/platforms/_http_client_limits.py

@@ -0,0 +1,84 @@
+"""Shared HTTP client factory for long-lived platform adapters.
+
+Gateway messaging platforms (QQ Bot, Feishu, WeCom, DingTalk, Signal,
+BlueBubbles, WeCom-callback) keep a persistent ``httpx.AsyncClient``
+alive for the adapter's lifetime.  That amortises TLS/connection setup
+across many API calls, but it also means the process's file-descriptor
+pressure is sensitive to how aggressively the pool recycles idle keep-
+alive connections.
+
+httpx's default ``keepalive_expiry`` is 5 seconds.  On macOS behind
+Cloudflare Warp (and other transparent proxies), peer-initiated FIN can
+sit in ``CLOSE_WAIT`` longer than that before the local socket actually
+drains — which, multiplied across 7 long-lived adapters plus the LLM
+client and MCP clients, walks straight into the default 256 fd limit.
+See #18451.
+
+``platform_httpx_limits()`` returns a tighter ``httpx.Limits`` the
+adapter factories use instead of the httpx default.  The values chosen:
+
+* ``max_keepalive_connections=10`` — plenty for any single adapter;
+  platform APIs rarely parallelise beyond this.
+* ``keepalive_expiry=2.0`` — close idle sockets aggressively so a
+  proxy's lingering CLOSE_WAIT window can't starve the process.
+
+Override via ``HERMES_GATEWAY_HTTPX_KEEPALIVE_EXPIRY`` /
+``HERMES_GATEWAY_HTTPX_MAX_KEEPALIVE`` env vars when tuning under load.
+"""
+
+from __future__ import annotations
+
+import os
+
+try:
+    import httpx
+except ImportError:  # pragma: no cover — optional dep
+    httpx = None  # type: ignore[assignment]
+
+
+_DEFAULT_KEEPALIVE_EXPIRY_S = 2.0
+_DEFAULT_MAX_KEEPALIVE = 10
+
+
+def platform_httpx_limits() -> "httpx.Limits | None":
+    """Return ``httpx.Limits`` tuned for persistent platform-adapter clients.
+
+    Returns ``None`` when httpx isn't importable, so callers can fall
+    back to httpx's built-in default without a hard dependency on this
+    helper being reachable.
+    """
+    if httpx is None:
+        return None
+
+    def _env_float(name: str, default: float) -> float:
+        raw = os.environ.get(name, "").strip()
+        if not raw:
+            return default
+        try:
+            val = float(raw)
+        except (TypeError, ValueError):
+            return default
+        return val if val > 0 else default
+
+    def _env_int(name: str, default: int) -> int:
+        raw = os.environ.get(name, "").strip()
+        if not raw:
+            return default
+        try:
+            val = int(raw)
+        except (TypeError, ValueError):
+            return default
+        return val if val > 0 else default
+
+    keepalive_expiry = _env_float(
+        "HERMES_GATEWAY_HTTPX_KEEPALIVE_EXPIRY", _DEFAULT_KEEPALIVE_EXPIRY_S
+    )
+    max_keepalive = _env_int(
+        "HERMES_GATEWAY_HTTPX_MAX_KEEPALIVE", _DEFAULT_MAX_KEEPALIVE
+    )
+
+    return httpx.Limits(
+        max_keepalive_connections=max_keepalive,
+        # Leave max_connections at httpx default (100) — plenty of headroom.
+        keepalive_expiry=keepalive_expiry,
+    )