Error map
53300 FATAL: sorry, too many clients already / remaining connection slots are reserved for non-replication superuser connections
PostgreSQL · 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)
PostgreSQL: could not connect to server / connection refused — Is the server running on host and accepting TCP/IP connections?
The client reached no PostgreSQL listener at that host/port — the server is down, listening elsewhere, or not accepting remote co…
FATAL: too many connections for role "x"
The role reached its per-role CONNECTION LIMIT (often set by hosting providers or free tiers).
MySQL ERROR 1040 (08004): Too many connections
MySQL reached `max_connections` and refuses new clients.
HTTP 508 Loop Detected (Resource Limit Is Reached)
Either the server detected an infinite loop (WebDAV) or — much more often — a cPanel/CloudLinux host is saying your account hit i…
server closed the connection unexpectedly — This probably means the server terminated abnormally before or while processing the request.
The connection to PostgreSQL dropped — the server restarted/crashed, a proxy/firewall killed an idle connection, or the backend w…
server does not support SSL, but SSL was required / no pg_hba.conf entry … no encryption
The client and server disagree about SSL — the client requires it but the server doesn’t offer it, or the server requires it and…
Azure: SkuNotAvailable / QuotaExceeded when creating a VM or resource
The VM size isn’t offered in that region/zone for your subscription, or you’ve hit the vCPU quota.
FATAL: database "x" does not exist
The connection names a database that isn’t on that server.
ERROR: could not extend file "base/…": No space left on device
The disk holding the PostgreSQL data directory (or WAL) is full.
HTTP 509 Bandwidth Limit Exceeded
A hosting-control-panel status (cPanel/Apache) meaning the account used up its monthly bandwidth allowance.
InsufficientInstanceCapacity: We currently do not have sufficient capacity in the Availability Zone you requested
AWS has no free capacity for that instance type in that Availability Zone right now.
Azure VM: AllocationFailed / ZonalAllocationFailed — Allocation failed. We do not have sufficient capacity for the requested VM size
Azure has no capacity for that VM size in the region/zone (or in the cluster the VM is pinned to) right now.
Two steps away (28)
MySQL ERROR 2002 (HY000): Can't connect to local MySQL server through socket
The client couldn’t reach the MySQL server — it isn’t running, or the client is looking for the socket/port in the wrong place.
PostgreSQL: FATAL: password authentication failed for user
PostgreSQL rejected the password for that role, or pg_hba.conf requires a different auth method.
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.
WordPress: Error Establishing a Database Connection
WordPress can’t connect to its MySQL/MariaDB database with the credentials in wp-config.php, or the database server is down.
Lock wait timeout exceeded; try restarting transaction (MySQL 1205)
A query waited too long for a row lock held by another transaction and gave up.
Too many open files (EMFILE)
The process hit its file-descriptor limit — sockets, files and pipes all count.
HTTP 429 Too Many Requests
You’ve hit a rate limit — too many requests in a given time window. Slow down and retry later.
HTTP 500 Internal Server Error
The server hit an unexpected condition — usually an unhandled exception or misconfiguration in the application.
HTTP 503 Service Unavailable
The server is temporarily unable to handle the request — overloaded, in maintenance, or has no healthy backends.
MySQL ERROR 2006 (HY000): MySQL server has gone away
The connection to MySQL was closed — usually by a timeout or a packet larger than `max_allowed_packet`.
HikariPool-1 - Connection is not available, request timed out after 30000ms
The connection pool was exhausted — all connections were busy for 30 seconds.
SSL: CERTIFICATE_VERIFY_FAILED / unable to get local issuer certificate
The client couldn’t verify the server’s TLS certificate chain, so it refused the HTTPS connection.
SSL error: tlsv1 alert protocol version / unsupported protocol / no protocols available
The client and server couldn’t agree on a TLS version or cipher, so the HTTPS handshake failed before any HTTP was exchanged.
ACM certificate stuck in Pending validation
ACM is waiting to see the DNS (or email) validation record — it wasn’t created, was created in the wrong DNS zone, or has a typo.
AWS: ThrottlingException / Rate exceeded
You exceeded the request rate for an AWS API; retry with exponential backoff.
Azure: AuthorizationFailed — The client does not have authorization to perform action
The signed-in identity (user, service principal or managed identity) lacks an Azure RBAC role for that action on that scope.
MySQL ERROR 1114 (HY000): The table 'x' is full
MySQL couldn’t extend the table — disk full, a size limit, or a MEMORY table hitting max_heap_table_size.
MySQL ERROR 1049 (42000): Unknown database 'x'
The database named in the connection doesn’t exist on that server.
ERROR: out of shared memory — HINT: You might need to increase max_locks_per_transaction.
A transaction took more locks than the lock table can hold — usually touching many tables/partitions at once.
API Error: Invalid or unsupported API version
The API version you requested — in the URL, a header or the SDK config — doesn’t exist or has been retired.
no space left on device (Docker / Linux)
The disk (or inode table) is full — Docker images, build cache, logs and volumes are common culprits.
Azure Storage: AuthorizationPermissionMismatch (403) — This request is not authorized to perform this operation using this permission
You’re accessing blob/queue data with Microsoft Entra ID, but the identity has only management roles (Owner/Contributor) — not a…
MySQL ERROR 126 (HY000): Incorrect key file for table; try to repair it
MySQL can’t use a table’s index file — usually a full tmp disk during a query, or MyISAM corruption.
HTTP 502 Bad Gateway
A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.
An error occurred (UnauthorizedOperation): You are not authorized to perform this operation. Encoded authorization failure message: ...
The IAM identity is missing an EC2 (or related) permission. The encoded message tells you exactly which action and resource were…
VcpuLimitExceeded: You have requested more vCPU capacity than your current vCPU limit
Your account’s On-Demand (or Spot) vCPU quota for that instance family and region is used up.
InvalidKeyPair.NotFound: The key pair 'x' does not exist
The key pair name you passed doesn’t exist in that region (key pairs are regional).
Azure VM: OSProvisioningTimedOut — OS Provisioning for VM did not finish in the allotted time
The VM booted but its guest agent didn’t report provisioning success in time — usually a generalisation problem with a custom ima…
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