Error map
AlreadyInitialized: already initialized MongoServerError: already initialized (rs.initiate on a configured replica set)
MongoDB · layer 5, Data
Centre: this error. First ring: errors it is linked with (7). 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 (7)
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.
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.
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: Transaction numbers are only allowed on a replica set member or mongos
You started a transaction (or used retryWrites) on a standalone MongoDB server, which doesn't support them.
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).
MongoDB: replSetInitiate quorum check failed: Could not connect to mongo2:27017 / No host described in new configuration 1 for replica set rs0 maps to this node
`rs.initiate()`/`rs.add()` couldn't reach a listed member or the config doesn't include the current node's hostname.
Two steps away (14)
MongoDB: Detected unclean shutdown - /var/lib/mongodb/mongod.lock is not empty
MongoDB wasn't shut down cleanly (crash/power loss), so it warns or refuses to start without recovery.
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.
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed it.
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).
MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
The MongoDB driver couldn’t find a reachable server for the connection string.
MongoServerError: WriteConflict error: this operation conflicted with another operation. Please retry your operation or multi-document transaction
Two operations tried to modify the same document at once; one was aborted with a transient error.
MongoServerError: Transaction 1 has been aborted / NoSuchTransaction: transaction has expired (transactionLifetimeLimitSeconds)
A transaction ran longer than the allowed lifetime (60 s default) or was aborted, so later operations fail.
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.
MongoDB: MongoServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
The driver couldn't connect to a MongoDB server on localhost:27017 — nothing is listening there.
MongoServerError: cursor id 1234567890 not found (CursorNotFound)
A cursor you were iterating timed out or was killed on the server, so the next batch fails.
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.
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).
Map another error
Popular: 500403400ORA-009331064Critical errorFileNotFoundException assemblyTypeError