Error map
Unclean shutdown: mongod.lock not empty / repair needed MongoDB: Detected unclean shutdown - /var/lib/mongodb/mongod.lock is not empty
MongoDB · 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.
Pod status Init:CrashLoopBackOff / Init:Error
An init container keeps failing, so the pod’s main containers never start.
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.
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…
mongod: Process exited with status 14 — Exception in initAndListen: IllegalOperation: Attempted to create a lock file on a read-only directory
`mongod` couldn't start because the data directory or log/socket file isn't writable or already locked.
MongoDB: We are too stale to use X as a sync source / replSet too stale to catch up — member in RECOVERING state
A secondary fell so far behind that the primary's oplog no longer covers the gap, so it can't resync by replaying.
MongoDB: WiredTiger error (28) [...] No space left on device / Fatal assertion 28558 ... disk full
MongoDB ran out of disk space on the data volume and stopped or refuses writes.
MongoServerSelectionError: Could not connect to any servers in your MongoDB Atlas cluster. One common reason is that you're trying to access the database from an IP that isn't whitelisted
Atlas rejects connections from IP addresses that aren't in the project's Network Access list.
MongoServerError: bad auth : Authentication failed. (Atlas user / special characters in password)
Atlas rejected the username/password in the connection string.
MongoDB: Out of memory: Killed process (mongod) — WiredTiger cache + queries exhausted RAM
The Linux OOM killer terminated `mongod` because the host ran out of memory.
MongoServerError: Exceeded memory limit for $group, but didn't allow external sort. Pass allowDiskUse:true to opt in
An aggregation stage needed more than 100 MB of RAM and spilling to disk wasn't enabled.
MongoServerError: BSONObj size: 17825792 (0x1100000) is invalid. Size must be between 0 and 16793600(16MB)
A single document (or an aggregation result row) grew past MongoDB's 16 MB limit.
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.
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…
java.lang.ExceptionInInitializerError
A static initializer (static block or static field) threw an exception while the class was loading.
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed 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.
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.
Docker: Bind for 0.0.0.0:80 failed: port is already allocated
Another container or host process already publishes that host port.
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).
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.
Error: listen EACCES: permission denied 0.0.0.0:80
Node isn’t allowed to bind that port — ports below 1024 need root on Linux/macOS, and some Windows ports are reserved.
MongoServerError: not primary and secondaryOk=false / NotWritablePrimary: not master
A write (or read without secondary preference) hit a secondary — the primary changed or you connected directly to a secondary.
MongoServerSelectionError: Server selection timed out after 30000 ms — topology type ReplicaSetNoPrimary
The driver sees the replica set members but none is a primary (election failing or members unreachable).
MongoServerSelectionError: Could not find host matching read preference { mode: "secondary" } for set rs0
The requested read preference (secondary, nearest with tags) matches no available member.
Pod stuck ContainerCreating: MountVolume.SetUp failed / Unable to attach or mount volumes: timed out waiting for the condition
The kubelet couldn’t mount one of the pod’s volumes, so the pod stays in ContainerCreating.
Multi-Attach error for volume: Volume is already exclusively attached to one node and can't be attached to another
A ReadWriteOnce volume (EBS, Azure Disk, PD) is still attached to another node, so the new pod on a different node can’t use it.
PersistentVolumeClaim stuck in Pending (no persistent volumes available / waiting for first consumer)
The PVC hasn’t been bound to a volume, so pods using it can’t be scheduled.
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
Error [ERR_STREAM_PREMATURE_CLOSE]: Premature close
A stream ended or was destroyed before it finished — often a client disconnect or upstream aborting a download.
TypeError: fetch failed (cause: ConnectTimeoutError / ECONNREFUSED / UND_ERR)
Node’s built-in fetch (undici) couldn’t complete the request; the real reason is in error.cause.
MongooseError: Operation `users.find()` buffering timed out after 10000ms
Mongoose queued a query waiting for a connection that never opened.
MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
The MongoDB driver couldn’t find a reachable server for the connection string.
MongoServerError: E11000 duplicate key error collection: db.users index: email_1 dup key
An insert/update violated a unique index in MongoDB.
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.
CastError: Cast to ObjectId failed for value "x" (type string) at path "_id"
A value that isn’t a valid 24-hex-character ObjectId was used in an _id query.
ValidationError: User validation failed: email: Path `email` is required.
A document failed Mongoose schema validation before saving.
Too many open files (EMFILE)
The process hit its file-descriptor limit — sockets, files and pipes all count.
Lambda: Request must be smaller than 6291456 bytes for the InvokeFunction operation (RequestEntityTooLargeException)
The event payload (or response) is over Lambda’s 6 MB synchronous limit (256 KB for async invocations).
Lambda: Unzipped size must be smaller than 262144000 bytes
The function code plus layers exceed Lambda’s 250 MB unzipped limit for zip deployments.
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