redis/redis-py · warning · ValueError

Given entry does not belong to the cache

Error message

Given entry does not belong to the cache

What it means

Raised as ValueError by LRUPolicy.touch (redis/cache.py:343) when the given cache_key is not present in the collection. touch() is meant to mark an existing LRU entry as most-recently-used (via move_to_end), so touching a key that was never inserted or has been evicted is rejected.

Source

Thrown at redis/cache.py:343

    def evict_many(self, count: int) -> List[CacheKey]:
        self._assert_cache()
        if count > len(self._cache.collection):
            raise ValueError("Evictions count is above cache size")

        popped_keys = []

        for _ in range(count):
            popped_entry = self._cache.collection.popitem(last=False)
            popped_keys.append(popped_entry[0])

        return popped_keys

    def touch(self, cache_key: CacheKey) -> None:
        self._assert_cache()

        if self._cache.collection.get(cache_key) is None:
            raise ValueError("Given entry does not belong to the cache")

        self._cache.collection.move_to_end(cache_key)

    def _assert_cache(self):
        if self.cache is None or not isinstance(self.cache, CacheInterface):
            raise ValueError("Eviction policy should be associated with valid cache.")


class EvictionPolicy(Enum):
    LRU = LRUPolicy


class CacheConfig(CacheConfigurationInterface):
    DEFAULT_CACHE_CLASS = DefaultCache
    DEFAULT_EVICTION_POLICY = EvictionPolicy.LRU
    DEFAULT_MAX_SIZE = 10000

    DEFAULT_ALLOW_LIST = [

View on GitHub (pinned to da03cdc7e8)

Solutions

1. Check membership (cache_key in cache.collection) before calling touch.
2. Only touch keys you just inserted or confirmed present.
3. Catch the ValueError and treat as a no-op / re-insert if the key should still be cached.

Example fix

# before
policy.touch(maybe_stale_key)  # ValueError if absent
# after
if maybe_stale_key in cache.collection:
    policy.touch(maybe_stale_key)

if cache_key in cache.collection:
    policy.touch(cache_key)

def key_in_cache(cache, key) -> bool:
    return key in cache.collection

try:
    policy.touch(cache_key)
except ValueError:
    pass  # already evicted; nothing to touch

When it happens

Trigger: Calling policy.touch(k) for a key that was never added, or that was already evicted; touch invoked on a stale key reference after the cache was pruned.

Common situations: Touching a key whose entry expired/evicted between read and touch; logic that touches keys without confirming membership; concurrent eviction removing the entry first.

Related errors

• Evictions count is above cache size
• Eviction policy should be associated with valid cache.
• Subcommand {subcommand_name} not found in command {command_n
• Command {command_name} not found in commands
• Invalid args in command: {command, *args}

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/ae9e8010bc4b29a1.json. Report an issue: GitHub.