fix(agent): cache runtime receipt readback under db pool pressure

apps/api/src/services/ai_agent_autonomous_runtime_control.py

@@ -9,6 +9,9 @@ KM, and Telegram receipts are present.
 
 from __future__ import annotations
 
+import asyncio
+import copy
+import time
 from collections.abc import Iterable, Mapping
 from datetime import UTC, datetime
 from typing import Any
@@ -42,6 +45,7 @@ _DEPLOY_ATTEMPT_NOTE = "cd_internal_control_plane_readback_retry_20260628_2"
 _LIVE_READBACK_SCHEMA_VERSION = "ai_agent_autonomous_runtime_receipt_readback_v1"
 _DEFAULT_PROJECT_ID = "awoooi"
 _DEFAULT_LOOKBACK_HOURS = 24
+_RUNTIME_RECEIPT_READBACK_CACHE_TTL_SECONDS = 20.0
 # CD cancel-stale-cd no-op triggers must not change runtime payloads.
 _EXECUTOR_OPERATION_TYPES = (
     "ansible_candidate_matched",
@@ -74,6 +78,11 @@ _PUBLIC_VALUE_REDACTIONS = (
 )
 
 logger = get_logger(__name__)
+_runtime_receipt_readback_cache: dict[
+    tuple[str, int, int],
+    tuple[float, dict[str, Any]],
+] = {}
+_runtime_receipt_readback_lock: asyncio.Lock | None = None
 
 
 def _allowed_risk_levels() -> list[str]:
@@ -125,6 +134,52 @@ def _int_value(value: Any) -> int:
         return 0
 
 
+def _runtime_receipt_readback_cache_key(
+    *,
+    project_id: str,
+    lookback_hours: int,
+    limit: int,
+) -> tuple[str, int, int]:
+    return (
+        project_id,
+        max(1, int(lookback_hours or _DEFAULT_LOOKBACK_HOURS)),
+        max(1, int(limit or 20)),
+    )
+
+
+def _get_runtime_receipt_readback_lock() -> asyncio.Lock:
+    global _runtime_receipt_readback_lock
+    if _runtime_receipt_readback_lock is None:
+        _runtime_receipt_readback_lock = asyncio.Lock()
+    return _runtime_receipt_readback_lock
+
+
+def _runtime_receipt_readback_cache_get(
+    key: tuple[str, int, int],
+) -> dict[str, Any] | None:
+    cached = _runtime_receipt_readback_cache.get(key)
+    if cached is None:
+        return None
+    stored_at, readback = cached
+    if time.monotonic() - stored_at > _RUNTIME_RECEIPT_READBACK_CACHE_TTL_SECONDS:
+        _runtime_receipt_readback_cache.pop(key, None)
+        return None
+    return copy.deepcopy(readback)
+
+
+def _runtime_receipt_readback_cache_store(
+    key: tuple[str, int, int],
+    readback: Mapping[str, Any],
+) -> None:
+    if readback.get("db_read_status") == "unavailable":
+        return
+    _runtime_receipt_readback_cache[key] = (time.monotonic(), copy.deepcopy(dict(readback)))
+
+
+def _clear_runtime_receipt_readback_cache() -> None:
+    _runtime_receipt_readback_cache.clear()
+
+
 def _sanitize_latest_rows(
     rows: Iterable[Mapping[str, Any] | Any],
     *,
@@ -3994,6 +4049,38 @@ async def load_ai_agent_autonomous_runtime_receipt_readback(
     project_id: str = _DEFAULT_PROJECT_ID,
     lookback_hours: int = _DEFAULT_LOOKBACK_HOURS,
     limit: int = 20,
+) -> dict[str, Any]:
+    """Read live executor receipts with short in-process DB pool protection."""
+
+    normalized_lookback_hours = max(1, int(lookback_hours or _DEFAULT_LOOKBACK_HOURS))
+    normalized_limit = max(1, int(limit or 20))
+    cache_key = _runtime_receipt_readback_cache_key(
+        project_id=project_id,
+        lookback_hours=normalized_lookback_hours,
+        limit=normalized_limit,
+    )
+    cached = _runtime_receipt_readback_cache_get(cache_key)
+    if cached is not None:
+        return cached
+
+    async with _get_runtime_receipt_readback_lock():
+        cached = _runtime_receipt_readback_cache_get(cache_key)
+        if cached is not None:
+            return cached
+        readback = await _load_ai_agent_autonomous_runtime_receipt_readback_uncached(
+            project_id=project_id,
+            lookback_hours=normalized_lookback_hours,
+            limit=normalized_limit,
+        )
+        _runtime_receipt_readback_cache_store(cache_key, readback)
+        return readback
+
+
+async def _load_ai_agent_autonomous_runtime_receipt_readback_uncached(
+    *,
+    project_id: str = _DEFAULT_PROJECT_ID,
+    lookback_hours: int = _DEFAULT_LOOKBACK_HOURS,
+    limit: int = 20,
 ) -> dict[str, Any]:
     """Read live executor receipts without sending messages or mutating runtime state."""