Error map
BUSY Redis is busy running a script Redis: (error) BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE
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)
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: (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.
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: 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: 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.
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 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.
Two steps away (35)
Azure AD (Entra ID): AADSTS700016 Application not found in the directory
The client ID in your sign-in request doesn’t exist in the tenant you’re authenticating against.
JWT Expired / Invalid Token
The JSON Web Token sent with the request is expired, malformed or signed with a different key, so the API rejects it (usually wit…
OAuth 2.0 Error: invalid_grant
The authorization code, refresh token or credentials sent to the token endpoint are invalid, expired, already used or were issued…
Error: Cannot find module 'x' (MODULE_NOT_FOUND)
Node can’t resolve the module path — the package isn’t installed, or a relative path/extension is wrong.
Error: listen EADDRINUSE: address already in use :::3000
Another process is already listening on that port.
SyntaxError: Cannot use import statement outside a module
An `import` statement ran in a context treated as CommonJS (Node without "type": "module", a browser script without type="module"…
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed it.
java.lang.OutOfMemoryError: Java heap space
The JVM ran out of heap memory and garbage collection couldn’t free enough.
Blue Screen: MEMORY_MANAGEMENT (Stop code 0x0000001A)
Windows detected a severe memory-management error — commonly faulty RAM, unstable memory settings or a bad driver.
pull access denied for image, repository does not exist or may require 'docker login'
Docker couldn’t pull the image: the name or tag is wrong, the repository is private and you’re not logged in, or it doesn’t exist…
unauthorized: authentication required (docker push / pull)
The registry needs credentials for this operation and the request had none or had expired ones.
denied: requested access to the resource is denied (docker push)
You’re logged in, but not allowed to push to that repository — usually the image isn’t tagged with your own username/organisation.
Laravel: SQLSTATE[HY000] [2002] Connection refused (SQL: select * from sessions) / php_network_getaddresses: getaddrinfo failed
Laravel can't open a network connection to the database host and port from `.env`.
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: 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.
Segmentation fault (core dumped)
A program accessed memory it wasn’t allowed to, and the kernel killed it with SIGSEGV (exit code 139).
Killed / Out of memory: Killed process (Linux OOM killer)
The kernel ran out of memory and killed a process to recover — the program just prints “Killed” (exit code 137).
FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
The V8 heap hit its limit — a large build (webpack, tsc, Next.js) needs more memory, or the app leaks.
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 listeners added
More than 10 listeners were added to one event — often a leak where listeners are added repeatedly.
MemoryError (Unable to allocate X GiB for an array)
Python couldn’t allocate memory — the data is larger than available RAM or address space.
The kernel appears to have died. It will restart automatically.
The Jupyter kernel process crashed — usually out of memory or a native library crash.
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: SLOWLOG GET shows KEYS * taking 1500000 microseconds — server blocked
Redis is single-threaded; one slow command delays everything else.
Redis: # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis
THP is enabled, which can cause latency spikes and high memory usage with Redis.
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: (error) LOADING Redis is loading the dataset in memory
Redis is starting and still reading its RDB/AOF, so it rejects commands temporarily.
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…
Redis Cluster: (error) CLUSTERDOWN Hash slot not served / The cluster is down
The cluster has hash slots that no node currently serves, so keys in those slots can't be accessed.
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.
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: (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) 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: (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`).
Redis: (error) EXECABORT Transaction discarded because of previous errors.
A command queued inside `MULTI` had a syntax error, so `EXEC` aborted the whole transaction.
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