Files
hermes-agent/gateway/platforms/_http_client_limits.py
T

58 lines
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Python

"""Shared HTTP client factory for long-lived platform adapters.
Persistent ``httpx.AsyncClient`` pools amortise TLS setup, but httpx's default
``keepalive_expiry`` (5s) lets peer-initiated FIN sit in ``CLOSE_WAIT`` behind
transparent proxies (macOS + Cloudflare Warp) — multiplied across 7 adapters
plus LLM/MCP clients that walks into the default 256 fd limit (#18451).
``platform_httpx_limits()`` returns a tighter ``httpx.Limits``:
``max_keepalive_connections=10`` (platform APIs rarely parallelise beyond
this), ``keepalive_expiry=2.0`` (close idle sockets aggressively).
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 _positive_env(name: str, default, cast):
"""``cast(env)`` when set, parseable and > 0; else *default*."""
raw = os.environ.get(name, "").strip()
if not raw:
return default
try:
val = cast(raw)
except (TypeError, ValueError):
return default
return val if val > 0 else default
def platform_httpx_limits() -> "httpx.Limits | None":
"""``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.
"""
if httpx is None:
return None
return httpx.Limits(
max_keepalive_connections=_positive_env(
"HERMES_GATEWAY_HTTPX_MAX_KEEPALIVE", _DEFAULT_MAX_KEEPALIVE, int
),
# max_connections stays at the httpx default (100) — plenty of headroom.
keepalive_expiry=_positive_env(
"HERMES_GATEWAY_HTTPX_KEEPALIVE_EXPIRY", _DEFAULT_KEEPALIVE_EXPIRY_S, float
),
)