Error map
Redis TLS: SSL handshake error / protocol mismatch Redis: Error: write EPROTO ... SSL routines:ssl3_get_record:wrong version number / Connection reset by peer (TLS vs plaintext)
Redis · layer 5, Data
Centre: this error. First ring: errors it is linked with (11). 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 (11)
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`.
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: (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.
Spring Data Redis: RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException
Spring/Lettuce couldn't connect to Redis at startup or runtime.
OpenSSL: error:1408F10B:SSL routines:ssl3_get_record:wrong version number
The peer did not answer with a TLS record — you spoke TLS to a plain HTTP/SMTP port (or the reverse), or a proxy intervened.
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.
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::CannotConnectError: Error connecting to Redis on localhost:6379 (Errno::ECONNREFUSED)
Sidekiq or the Rails Redis cache/cable couldn't connect to Redis.
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.
Rails: ActiveRecord::ConnectionNotEstablished: No connection pool for 'ActiveRecord::Base' found
ActiveRecord has no database connection configured or established for this process.
Two steps away (31)
Python: ConnectionRefusedError: [Errno 111] Connection refused — smtplib connect to localhost:25
Nothing is listening on the SMTP host and port your script connected to — often `localhost:25` because no host was given and no l…
Nodemailer: Error: connect ETIMEDOUT 142.250.27.108:465 (code: 'ETIMEDOUT', command: 'CONN')
Nodemailer could not open a connection to the SMTP server before the timeout — a blocked port, wrong host, or network issue.
Laravel: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'x@example.com' for key 'users_email_unique'
The query violated a database constraint — a duplicate value in a unique column or a missing/blocked foreign key.
ReplyError: NOAUTH Authentication required.
The Redis server requires a password (or ACL user) but the client didn’t authenticate.
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.
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.
Redis: Closing idle client / Connection closed by server after timeout 300
Redis' `timeout` directive closes connections idle longer than N seconds.
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.
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: 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.
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).
ERR_SSL_PROTOCOL_ERROR (This site can't provide a secure connection)
The browser couldn’t negotiate TLS — the server sent an invalid response, often plain HTTP on the HTTPS port.
cURL error 35: OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to host:443
The TLS handshake failed — protocol/cipher mismatch, a proxy interfering, or the server closed the connection.
SMTP: [SSL: WRONG_VERSION_NUMBER] wrong version number — SMTP over SSL on a STARTTLS port
Your client tried to start TLS immediately on a port where the server speaks plain SMTP first (or the reverse), so the handshake…
WordPress: Error establishing a Redis connection (object cache)
The persistent object cache drop-in (object-cache.php) can’t connect to Redis, so the whole site fails.
Laravel/PHP 8: ErrorException: Attempt to read property "name" on null
You accessed a property on a value that is `null`, typically an empty relationship or a query that found nothing.
Laravel/PHP: Allowed memory size of 134217728 bytes exhausted (tried to allocate 20480 bytes) in vendor/laravel/framework
A request (or artisan job) used more memory than PHP's `memory_limit` allows.
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: 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: 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: # 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: # Failed opening the temp RDB file temp-1234.rdb (in server root dir /var/lib/redis) for saving: Permission denied
Redis can't write its snapshot file to the configured directory.
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: (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.
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.
Rails: ActionController::InvalidAuthenticityToken (Can't verify CSRF token authenticity)
A non-GET request arrived without a valid CSRF token for the session.
Ruby: NameError: uninitialized constant UsersController::User (Did you mean? Users)
Ruby (or Rails autoloading) couldn't find a class or module with that name in the current scope.
Ruby: NameError: undefined local variable or method 'x' for main:Object
Ruby saw a bare identifier that is neither a local variable nor a method on the current object.
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