SurfSense/surfsense_backend/app/indexing_pipeline/cache/eviction/task.py

68 lines
2.5 KiB
Python

"""Celery task that prunes the index cache by TTL, then by size budget."""
from __future__ import annotations
import contextlib
import logging
from datetime import UTC, datetime, timedelta
from app.celery_app import celery_app
from app.etl_pipeline.cache.eviction.policy import select_over_budget
from app.etl_pipeline.cache.schemas import EvictionCandidate
from app.indexing_pipeline.cache.persistence import CachedEmbeddingSetRepository
from app.indexing_pipeline.cache.settings import load_index_cache_settings
from app.indexing_pipeline.cache.storage import EmbeddingCacheStore
from app.observability import metrics
from app.tasks.celery_tasks import get_celery_session_maker, run_async_celery_task
logger = logging.getLogger(__name__)
@celery_app.task(name="evict_index_cache")
def evict_index_cache_task():
return run_async_celery_task(_evict)
async def _evict() -> None:
"""Expire stale entries, then shed the coldest overflow only if still over budget."""
settings = load_index_cache_settings()
if not settings.enabled:
return
store = EmbeddingCacheStore()
async with get_celery_session_maker()() as session:
index = CachedEmbeddingSetRepository(session)
cutoff = datetime.now(UTC) - timedelta(days=settings.ttl_days)
expired = await index.select_expired(
cutoff=cutoff, limit=settings.eviction_batch
)
await _drop(index, store, expired, phase="ttl")
total = await index.total_size_bytes()
if total > settings.max_total_bytes:
coldest = await index.select_coldest(limit=settings.eviction_batch)
over_budget = select_over_budget(
coldest,
current_total_bytes=total,
max_total_bytes=settings.max_total_bytes,
)
await _drop(index, store, over_budget, phase="size")
async def _drop(
index: CachedEmbeddingSetRepository,
store: EmbeddingCacheStore,
candidates: list[EvictionCandidate],
*,
phase: str,
) -> None:
if not candidates:
return
for candidate in candidates:
# Drop the index row even if the blob delete fails (orphan blob is harmless).
with contextlib.suppress(Exception):
await store.delete(candidate.storage_key)
await index.delete_by_ids([candidate.id for candidate in candidates])
metrics.record_index_cache_eviction(len(candidates), phase=phase)
logger.info("Evicted %d cached embedding sets (%s)", len(candidates), phase)