Error map
Redis fails to start: Address already in use / Bad directive in config Redis: # Could not create server TCP listening socket *:6379: bind: Address already in use / *** FATAL CONFIG FILE ERROR ***
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)
[nodemon] app crashed - waiting for file changes before starting...
Your app threw an error on startup; nodemon is waiting for a file change to retry.
java.lang.ExceptionInInitializerError
A static initializer (static block or static field) threw an exception while the class was loading.
Pod status Init:CrashLoopBackOff / Init:Error
An init container keeps failing, so the pod’s main containers never start.
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
Nginx (or another server) can’t listen on the port because another process already holds it — often Apache, another Nginx, or a s…
Docker container exits immediately (Exited (0) / Exited (1) right after start)
The container started and its main process finished at once, so the container stopped — Docker containers only live as long as PI…
Docker container keeps restarting (Restarting (1) x seconds ago)
The container crashes on start and its restart policy (always/unless-stopped/on-failure) starts it again in a loop.
Redis: (error) ERR CONFIG SET failed (possibly related to argument 'maxmemory') - can't set immutable config
`CONFIG SET` rejected the parameter — it is immutable at runtime, invalid, or disabled by the hosting provider.
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: 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: # 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) 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::CannotConnectError: Error connecting to Redis on localhost:6379 (Errno::ECONNREFUSED)
Sidekiq or the Rails Redis cache/cable couldn't connect to Redis.
Two steps away (36)
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.
HTTP Error 500.30 - ASP.NET Core app failed to start
IIS/Azure’s ASP.NET Core Module launched your app but it crashed during startup.
Job for mysql.service failed because the control process exited with error code
The MySQL/MariaDB service failed to start — the real reason is in the MySQL error log.
FATAL: the database system is starting up
PostgreSQL is still starting (or recovering) and not accepting connections yet.
FATAL: lock file "postmaster.pid" already exists — Is another postmaster running in data directory?
PostgreSQL won’t start because a stale postmaster.pid file remains (or another instance really is running).
Kubernetes: CrashLoopBackOff
The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.
Kubernetes: CreateContainerConfigError — secret / configmap not found
Kubernetes can’t build the container’s configuration — usually a referenced Secret, ConfigMap or key doesn’t exist in that namesp…
Pod status InvalidImageName: couldn't parse image reference
The image field in the pod spec isn’t a valid image reference, so the kubelet can’t even try to pull it.
Docker: Bind for 0.0.0.0:80 failed: port is already allocated
Another container or host process already publishes that host port.
HTTP 403 Forbidden
The server understood the request but refuses to authorize it — you (or the server process) are not allowed to access this resour…
Web server failed to start. Port 8080 was already in use.
Spring Boot couldn’t bind its embedded server port because another process uses it.
Conflict. The container name "/x" is already in use by container …
A container (running or stopped) already has that name; Docker won’t create a second one with the same name.
LOG: could not bind IPv4 address "0.0.0.0": Address already in use — Is another postmaster already running on port 5432?
Another process (often a second PostgreSQL install or a container) already listens on 5432.
ECS task stopped: CannotPullContainerError: pull image manifest has been retried ... / ref pull has been retried
The ECS task couldn’t pull its image — no network route to the registry, missing ECR permissions, or a wrong image tag.
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed it.
Error response from daemon: Container X is not running
You tried to exec into or interact with a container that has stopped.
Docker container is unhealthy (health check failing)
The container is running, but its HEALTHCHECK command keeps failing, so Docker (and dependent services) consider it unhealthy.
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: Closing idle client / Connection closed by server after timeout 300
Redis' `timeout` directive closes connections idle longer than N seconds.
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.
ReplyError: NOAUTH Authentication required.
The Redis server requires a password (or ACL user) but the client didn’t authenticate.
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.
Error response from daemon: network X not found
The container or Compose project refers to a Docker network that doesn’t exist (any more).
Error response from daemon: Pool overlaps with other one on this address space
Docker tried to create a network whose subnet clashes with an existing Docker network (or a VPN/host route).
driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name
Docker’s iptables rules were wiped (firewalld/ufw reload, iptables flush) while Docker was running, so it can’t publish ports.
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
The docker CLI can’t talk to the Docker engine — it isn’t running, or your user can’t access the socket.
user is not in the sudoers file. This incident will be reported.
Your account isn’t allowed to use sudo.
java.nio.file.AccessDeniedException: /path
The OS denied a file operation to the Java process.
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 wrong number of arguments for 'set' command / ERR syntax error
The command was malformed: missing/extra arguments or an unsupported option for your Redis version.
Redis: (error) ERR This instance has cluster support disabled
A cluster command (or cluster client) was used against a standalone Redis instance.
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: 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.
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