Reference library

Caching & Redis

Cache-aside, TTL, invalidation, hot keys, and in-memory lookup patterns at scale.

1 match
Caching & Redis hard

Coalescing duplicate in-flight requests: one shared result for concurrent callers

Runs identical concurrent requests through a single shared call, caching the result while it's in flight and returning the same value to all callers.

concurrency threading coalescing
Python 
import time
import threading
from collections import defaultdict


class CoalescingExecutor:
    def __init__(self):
        self._locks = defaultdict(threading.Lock)
        self._in_flight = {}

    def execute(self, key, func):
        with self._locks[key]:
            if key in self._in_flight:
                re…
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