Error map
CLUSTERDOWN Hash slot not served Redis Cluster: (error) CLUSTERDOWN Hash slot not served / The cluster is down
Redis · layer 5, Data
Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (12)
Redis: (error) BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE
A long-running Lua script (or function) blocks the single-threaded server, so other commands are rejected.
Redis Sentinel: # -failover-abort-no-good-slave master mymaster 10.0.0.5 6379 / +sdown master
Sentinel detected the master as down but found no healthy replica to promote.
Redis: (error) MOVED 3999 10.0.0.6:6379 / ReplyError: MOVED 12182 192.168.0.5:7001
The key lives on another cluster node, and the client isn't cluster-aware, so it just sees the redirect.
Redis Cluster: (error) CROSSSLOT Keys in request don't hash to the same slot
A multi-key command or transaction used keys that live in different cluster slots.
Redis: (error) NOSCRIPT No matching script. Please use EVAL.
`EVALSHA` referenced a script hash the server doesn't have cached (after restart, failover, or `SCRIPT FLUSH`).
Redlock: ExecutionError: The operation was unable to achieve a quorum during its retry window / LockError: Exceeded 10 attempts to lock the resource
A distributed lock couldn't be acquired because another holder keeps it or too few Redis nodes responded.
Celery: Task executed twice / Restoring unacked messages — Redis broker visibility_timeout shorter than task ETA
Celery's Redis transport redelivers a task if it isn't acknowledged within `visibility_timeout` (1 hour by default).
Redis: SLOWLOG GET shows KEYS * taking 1500000 microseconds — server blocked
Redis is single-threaded; one slow command delays everything else.
BullMQ: Error: Missing lock for job 42. moveToFinished / job stalled more than allowable limit
A BullMQ worker lost the lock on a job (it took too long or the event loop was blocked), so the job is considered stalled.
Redis: (error) ERR This instance has cluster support disabled
A cluster command (or cluster client) was used against a standalone Redis instance.
Redis::CannotConnectError: Error connecting to Redis on localhost:6379 (Errno::ECONNREFUSED)
Sidekiq or the Rails Redis cache/cable couldn't connect to Redis.
Redis: Client id=7 scheduled to be closed ASAP for overcoming of output buffer limits (replica) / MASTER <-> REPLICA sync: Timeout
A replica can't finish the initial sync because the master's replication buffer fills up or the transfer times out, so it restart…
Two steps away (29)
ReplyError: NOAUTH Authentication required.
The Redis server requires a password (or ACL user) but the client didn’t authenticate.
WRONGTYPE Operation against a key holding the wrong kind of value
A Redis command was used on a key of a different type (e.g. HGET on a string key).
Redis: OOM command not allowed when used memory > 'maxmemory'
Redis reached its maxmemory limit and the eviction policy (noeviction) refuses new writes.
Redis: READONLY You can't write against a read only replica
The client is connected to a replica (or a failed-over node) and tried to write.
Redis replica: (error) MASTERDOWN Link with MASTER is down and replica-serve-stale-data is set to 'no'
A replica lost its connection to the master and refuses to serve possibly stale data.
redis-py: redis.sentinel.MasterNotFoundError: No master found for 'mymaster' / ioredis: All sentinels are unreachable
The client asked Sentinels for the current master but got none (names wrong, sentinels down/unreachable, or failover in progress).
Redis: Error: connect ECONNREFUSED 127.0.0.1:6379 / Could not connect to Redis at 127.0.0.1:6379: Connection refused
Nothing is listening on the Redis host/port your client uses.
Redis: (error) ERR DB index is out of range / ERR SELECT is not allowed in cluster mode
`SELECT n` used a database number the server doesn't have, or you're on Redis Cluster/managed Redis that only has DB 0.
Redis: (error) EXECABORT Transaction discarded because of previous errors.
A command queued inside `MULTI` had a syntax error, so `EXEC` aborted the whole transaction.
Redis: Client id=12 addr=10.0.0.5:51234 scheduled to be closed ASAP for overcoming of output buffer limits
A client (often a slow subscriber or a replica) couldn't read data fast enough, so Redis disconnected it to protect memory.
Redis: (error) ERR unknown command 'JSON.GET', with args beginning with: / unknown command 'FT.SEARCH'
The server doesn't know the command — wrong name, newer Redis version, or a missing module.
Redis client: Error: Command timed out / redis.exceptions.TimeoutError: Timeout reading from socket
The client waited longer than its timeout for a Redis reply.
ioredis: MaxRetriesPerRequestError: Reached the max retries per request limit (which is 20). Refer to "maxRetriesPerRequest" option for details
ioredis tried to run a command 20 times while the connection was down and gave up.
Redis: DENIED Redis is running in protected mode because protected mode is enabled and no password is set for the default user
Redis refuses connections from non-local clients when it has no password and is bound to all interfaces.
Redis: (error) NOAUTH Authentication required. / WRONGPASS invalid username-password pair or user is disabled
The server requires a password (or ACL user) and the client sent none or the wrong one.
Redis: Error: read ECONNRESET / redis.exceptions.ConnectionError: Connection reset by peer after idle time
A middlebox or Redis closed an idle connection, and the pooled client reused it.
Docker build slow: "Sending build context to Docker daemon 2.5GB" / transferring context takes forever
docker build is uploading your whole project folder — node_modules, .git, data files — before building, because there’s no (or a…
Laravel: Symfony\Component\ErrorHandler\Error\FatalError: Maximum execution time of 30 seconds exceeded
A web request ran longer than PHP's `max_execution_time` and was killed.
Redis: INFO memory — mem_fragmentation_ratio:2.8 (RSS much larger than used_memory)
The process uses far more RSS than the data size, due to allocator fragmentation or deleted-but-not-returned memory.
Laravel Queue: Illuminate\Queue\MaxAttemptsExceededException: App\Jobs\SendReport has been attempted too many times or run too long
A queued job failed repeatedly or ran past its timeout, so it was marked failed.
Redis: Error: write EPROTO ... SSL routines:ssl3_get_record:wrong version number / Connection reset by peer (TLS vs plaintext)
The client and server disagree about TLS — plaintext client to a TLS port, or TLS client to a plaintext port.
Redis: ERR max number of clients reached
Redis hit its `maxclients` limit (default 10000, lower if the OS limit is low), so new connections are refused.
Laravel: .env changes ignored / env('X') returns null after php artisan config:cache
After `config:cache`, Laravel no longer reads `.env`, so `env()` calls outside config files return null and edits to `.env` have…
Redis: Could not connect to Redis at 10.0.0.5:6379: Connection timed out
Redis only listens on localhost by default, so remote clients time out or are refused.
Redis: Closing idle client / Connection closed by server after timeout 300
Redis' `timeout` directive closes connections idle longer than N seconds.
Laravel: Predis\Connection\ConnectionException: Connection refused [tcp://127.0.0.1:6379] / RedisException: Connection refused
Laravel can't connect to Redis, which it uses for cache, sessions or queues.
Redis: evicted_keys growing — keys vanish unexpectedly because maxmemory is reached and a volatile/allkeys eviction policy is active
Redis removed keys to stay under `maxmemory` according to the eviction policy.
Redis: # Can't save in background: fork: Cannot allocate memory / WARNING overcommit_memory is set to 0!
Redis couldn't fork to write an RDB/AOF snapshot because the OS refused to allocate memory.
Redis: (error) LOADING Redis is loading the dataset in memory
Redis is starting and still reading its RDB/AOF, so it rejects commands temporarily.
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