Files
DECNET/decnet/web/router/stats/api_get_stats.py
anti 6301504c0e perf(api): TTL-cache /stats + unfiltered pagination counts
Every /stats call ran SELECT count(*) FROM logs + SELECT count(DISTINCT
attacker_ip) FROM logs; every /logs and /attackers call ran an
unfiltered count for the paginator. At 500 concurrent users these
serialize through aiosqlite's worker threads and dominate wall time.

Cache at the router layer (repo stays dialect-agnostic):
  - /stats response: 5s TTL
  - /logs total (only when no filters): 2s TTL
  - /attackers total (only when no filters): 2s TTL

Filtered paths bypass the cache. Pattern reused from api_get_config
and api_get_health (asyncio.Lock + time.monotonic window + lazy lock).
2026-04-17 19:09:15 -04:00

51 lines
1.7 KiB
Python

import asyncio
import time
from typing import Any, Optional
from fastapi import APIRouter, Depends
from decnet.telemetry import traced as _traced
from decnet.web.dependencies import require_viewer, repo
from decnet.web.db.models import StatsResponse
router = APIRouter()
# /stats is aggregate telemetry polled constantly by the UI and locust.
# A 5s window collapses thousands of concurrent calls — each of which
# runs SELECT count(*) FROM logs + SELECT count(DISTINCT attacker_ip) —
# into one DB hit per window.
_STATS_TTL = 5.0
_stats_cache: tuple[Optional[dict[str, Any]], float] = (None, 0.0)
_stats_lock: Optional[asyncio.Lock] = None
def _reset_stats_cache() -> None:
global _stats_cache, _stats_lock
_stats_cache = (None, 0.0)
_stats_lock = None
async def _get_stats_cached() -> dict[str, Any]:
global _stats_cache, _stats_lock
value, ts = _stats_cache
now = time.monotonic()
if value is not None and now - ts < _STATS_TTL:
return value
if _stats_lock is None:
_stats_lock = asyncio.Lock()
async with _stats_lock:
value, ts = _stats_cache
now = time.monotonic()
if value is not None and now - ts < _STATS_TTL:
return value
value = await repo.get_stats_summary()
_stats_cache = (value, time.monotonic())
return value
@router.get("/stats", response_model=StatsResponse, tags=["Observability"],
responses={401: {"description": "Could not validate credentials"}, 403: {"description": "Insufficient permissions"}, 422: {"description": "Validation error"}},)
@_traced("api.get_stats")
async def get_stats(user: dict = Depends(require_viewer)) -> dict[str, Any]:
return await _get_stats_cached()