System Errors

This page documents all non-JetStream errors that the NATS server can return to clients, routes, gateways, and leafnode connections.

Authentication and Authorization Errors

Error	Constant	Description
Authentication expired	ErrAuthExpired	An expired authorization due to timeout.
Proxy is not trusted	ErrAuthProxyNotTrusted	An error condition on failed authentication due to a connection from a proxy not in the list of trusted proxies.
Proxy connection required	ErrAuthProxyRequired	An error condition on failed authentication due to a connection not coming from a proxy.
Authentication timeout	ErrAuthTimeout	An error condition on failed authorization due to timeout.
Authentication error	ErrAuthentication	An error condition on failed authentication.
Credentials have been revoked	ErrRevocation	Returned when a credential has been revoked.
Service import not authorized	ErrServiceImportAuthorization	Returned when a service import is not authorized.
Stream import not authorized	ErrStreamImportAuthorization	Returned when a stream import is not authorized.
Authorization Violation	Authorization Violation	Client attempted an operation that violates configured permissions
User Authentication Expired	User Authentication Expired	User JWT or credentials have expired
Account Authentication Expired	Account Authentication Expired	Account authentication has expired
User Authentication Revoked	User Authentication Revoked	User credentials have been revoked
Permissions Violation for Publish	Permissions Violation for Publish	Client attempted to publish to a subject without permission
Permissions Violation for Subscription	Permissions Violation for Subscription	Client attempted to subscribe to a subject without permission

Connection Limit Errors

Error	Constant	Description
Maximum account active connections exceeded	ErrTooManyAccountConnections	That an account has reached its maximum number of active connections.
Maximum connections exceeded	ErrTooManyConnections	A client that the maximum number of connections supported by the server has been reached.
Maximum subscriptions exceeded	ErrTooManySubs	A client that the maximum number of subscriptions per connection has been reached.
Connection Throttling Is Active	Connection Throttling Is Active	Server is actively throttling new connections
Maximum Clients Exceeded	Maximum Clients Exceeded	Server has reached its maximum number of allowed clients

Protocol and Payload Errors

Error	Constant	Description
Invalid client protocol	ErrBadClientProtocol	A client requested an invalid client protocol.
Bad message header detected	ErrBadMsgHeader	The parser detected a bad message header
Maximum control line exceeded	ErrMaxControlLine	An error condition when the control line is too big.
Maximum payload exceeded	ErrMaxPayload	An error condition when the payload is too big.
Message headers not supported	ErrMsgHeadersNotSupported	The parser detected a message header but they are not supported on this server.
No responders requires headers support	ErrNoRespondersRequiresHeaders	That a client needs to have headers on if they want no responders behavior.
Maximum Payload Violation	Maximum Payload Violation	Published message exceeds the configured maximum payload size
Protocol Violation	Protocol Violation	Client violated the NATS protocol
Parser Error	Parser Error	Server encountered an error parsing client protocol

Subject and Publishing Errors

Error	Constant	Description
Invalid publish subject	ErrBadPublishSubject	An error condition for an invalid publish subject.
Bad qualifier	ErrBadQualifier	Used to error on a bad qualifier for a transform.
Invalid subject	ErrBadSubject	An error condition for an invalid subject.
Invalid mapping destination	ErrInvalidMappingDestination	Used for all subject mapping destination errors
Invalid transform	ErrInvalidMappingDestinationSubject	Used to error on a bad transform destination mapping
Malformed subject	ErrMalformedSubject	Returned when a subscription is made with a subject that does not conform to subject rules.
Wildcard index out of range	ErrMappingDestinationIndexOutOfRange	Returned when the mapping destination function is passed an out of range wildcard index value for one of it's arguments
Function argument is invalid or in the wrong format	ErrMappingDestinationInvalidArg	Returned when the mapping destination function is passed and invalid argument
Not enough arguments passed to the function	ErrMappingDestinationNotEnoughArgs	Returned when the mapping destination function is not passed enough arguments
The only mapping function allowed for import transforms is {{Wildcard()}}	ErrMappingDestinationNotSupportedForImport	Returned when you try to use a mapping function other than wildcard in a transform that needs to be reversible (i.e. an import)
Not using all of the token wildcard(s)	ErrMappingDestinationNotUsingAllWildcards	Used to error on a transform destination not using all of the token wildcards
Too many arguments passed to the function	ErrMappingDestinationTooManyArgs	Returned when the mapping destination function is passed too many arguments
No matching transforms available	ErrNoTransforms	No subject transforms are available to map this subject.
Reserved account	ErrReservedAccount	A reserved account that can not be created.
Reserved internal subject	ErrReservedPublishSubject	An error condition when sending to a reserved subject, e.g. _SYS.>
Subject has exceeded number of tokens limit	ErrTooManySubTokens	A client that the subject has too many tokens.
Unknown function	ErrUnknownMappingDestinationFunction	Returned when a subject mapping destination contains an unknown mustache-escaped mapping function.
Invalid Subscription	Invalid Subscription	Subscription request is invalid

TLS and Security Errors

Error	Constant	Description
Certificate not pinned	ErrCertNotPinned	Returned when pinned certs are set and the certificate is not in it
Secure Connection - TLS Required	Secure Connection - TLS Required	Server requires TLS but client attempted non-TLS connection
TLS Handshake Error	TLS Handshake Error	TLS handshake with client failed

Account Errors

Error	Constant	Description
Account exists	ErrAccountExists	Returned when an account is attempted to be registered but already exists.
Account expired	ErrAccountExpired	Returned when an account has expired.
Account resolver no new claims	ErrAccountResolverSameClaims	Returned when same claims have been fetched.
Account resolver update too soon	ErrAccountResolverUpdateTooSoon	Returned when we attempt an update too soon to last request.
Account validation failed	ErrAccountValidation	Returned when an account has failed validation.
Bad account	ErrBadAccount	A malformed or incorrect account.
Bad sampling percentage, should be 1-100	ErrBadSampling	Returned when the sampling for latency tracking is not 1 >= sample <= 100.
Bad service response type	ErrBadServiceType	Returned when latency tracking is being applied to non-singleton response types.
Import forms a cycle	ErrImportFormsCycle	Returned when an import would form a cycle.
Account missing	ErrMissingAccount	Returned when an account does not exist.
Service missing	ErrMissingService	Returned when an account does not have an exported service.
Account resolver missing	ErrNoAccountResolver	Returned when we attempt an update but do not have an account resolver.
System account not setup	ErrNoSysAccount	Returned when an attempt to publish or subscribe is made when there is no internal system account defined.
Stream import prefix can not contain wildcard tokens	ErrStreamImportBadPrefix	Returned when a stream import prefix contains wildcards.
Stream import already exists	ErrStreamImportDuplicate	Returned when a stream import is a duplicate of one that already exists.
Failed Account Registration	Failed Account Registration	Failed to register client with account

Server Name and Cluster Errors

Error	Constant	Description
Cluster name conflicts between cluster and gateway definitions	ErrClusterNameConfigConflict	That the options for cluster name in cluster and gateway are in conflict.
Cluster name cannot contain spaces	ErrClusterNameHasSpaces	That the cluster name contains spaces, which is not allowed.
Cluster name from remote server conflicts	ErrClusterNameRemoteConflict	That a remote server has a different cluster name.
Duplicate server name	ErrDuplicateServerName	Returned when processing a server remote connection and the server reports that this server name is already used in the cluster.
Gateway name cannot contain spaces	ErrGatewayNameHasSpaces	That the gateway name contains spaces, which is not allowed.
Remote leafnode has same cluster name	ErrLeafNodeHasSameClusterName	An error condition when a leafnode is a cluster and it has the same cluster name as the hub cluster.
Server name cannot contain spaces	ErrServerNameHasSpaces	That the server name contains spaces, which is not allowed.

Wrong Port Connection Errors

Error	Constant	Description
Attempted to connect to leaf node port	ErrClientConnectedToLeafNodePort	An error condition when a client attempted to connect to the leaf node listen port.
Attempted to connect to route port	ErrClientConnectedToRoutePort	An error condition when a client attempted to connect to the route listen port.
Attempted to connect to gateway port	ErrClientOrRouteConnectedToGatewayPort	An error condition when a client or route attempted to connect to the Gateway port.
Attempted to connect to wrong port	ErrConnectedToWrongPort	An error condition when a connection is attempted to the wrong listen port (for instance a LeafNode to a client port, etc...)

Gateway-Specific Errors

Error	Constant	Description
Wrong gateway	ErrWrongGateway	An error condition when a server receives a connect request from a remote Gateway with a destination name that does not match the server's Gateway's name.
Connection to Gateway Rejected	Connection to Gateway Rejected	Gateway rejected the connection

Leafnode-Specific Errors

Error	Constant	Description
Leafnodes disabled	ErrLeafNodeDisabled	When we disable leafnodes.
Leafnode loop detected	ErrLeafNodeLoop	A leafnode is trying to register for a cluster we already have registered.

Connection State Errors

Error	Constant	Description
Connection closed	ErrConnectionClosed	An error condition on a closed connection.
Server is not running	ErrServerNotRunning	Used to signal an error that a server is not running.
Stale Connection	Stale Connection	Connection is stale and will be closed

Other Errors

Error	Constant	Description
Search cycle depth exhausted	ErrCycleSearchDepth	Returned when we have exceeded our maximum search depth..
Minimum version required	ErrMinimumVersionRequired	Returned when a connection is not at the minimum version required.
Subscribe permission violation	ErrSubscribePermissionViolation	Returned when processing of a subscription fails due to permissions.

Route-Specific Errors

Error	Constant	Description
Route Authorization Violation	Route Authorization Violation	Route connection failed authorization
Duplicate Route	Duplicate Route	Route connection already exists to this server

Slow Consumer and Flow Control

Error	Constant	Description
Slow Consumer Detected	Slow Consumer Detected	Server detected a slow consumer that is not keeping up with message delivery
Consumer Is Slow	Consumer Is Slow	Consumer is processing messages too slowly
Write Deadline Exceeded	Write Deadline Exceeded	Write operation to client exceeded the configured deadline

Connection Close Reasons

These are the reasons a client connection may be closed by the server. They appear in monitoring data and disconnect events.

Error	Constant	Description
Client Closed	ClientClosed	Client Closed
Authentication Timeout	AuthenticationTimeout	Authentication Timeout
Authentication Failure	AuthenticationViolation	Authentication Failure
TLS Handshake Failure	TLSHandshakeError	TLS Handshake Failure
Slow Consumer (Pending Bytes)	SlowConsumerPendingBytes	Slow Consumer (Pending Bytes)
Slow Consumer (Write Deadline)	SlowConsumerWriteDeadline	Slow Consumer (Write Deadline)
Write Error	WriteError	Write Error
Read Error	ReadError	Read Error
Parse Error	ParseError	Parse Error
Stale Connection	StaleConnection	Stale Connection
Protocol Violation	ProtocolViolation	Protocol Violation
Bad Client Protocol Version	BadClientProtocolVersion	Bad Client Protocol Version
Incorrect Port	WrongPort	Incorrect Port
Maximum Account Connections Exceeded	MaxAccountConnectionsExceeded	Maximum Account Connections Exceeded
Maximum Connections Exceeded	MaxConnectionsExceeded	Maximum Connections Exceeded
Maximum Message Payload Exceeded	MaxPayloadExceeded	Maximum Message Payload Exceeded
Maximum Control Line Exceeded	MaxControlLineExceeded	Maximum Control Line Exceeded
Maximum Subscriptions Exceeded	MaxSubscriptionsExceeded	Maximum Subscriptions Exceeded
Duplicate Route	DuplicateRoute	Duplicate Route
Route Removed	RouteRemoved	Route Removed
Server Shutdown	ServerShutdown	Server Shutdown
Authentication Expired	AuthenticationExpired	Authentication Expired
Wrong Gateway	WrongGateway	Wrong Gateway
Missing Account	MissingAccount	Missing Account
Credentials Revoked	Revocation	Credentials Revoked
Internal Client	InternalClient	Internal Client
Message Header Violation	MsgHeaderViolation	Message Header Violation
No Responders Requires Headers	NoRespondersRequiresHeaders	No Responders Requires Headers
Cluster Name Conflict	ClusterNameConflict	Cluster Name Conflict
Duplicate Remote LeafNode Connection	DuplicateRemoteLeafnodeConnection	Duplicate Remote LeafNode Connection
Duplicate Client ID	DuplicateClientID	Duplicate Client ID
Duplicate Server Name	DuplicateServerName	Duplicate Server Name
Minimum Version Required	MinimumVersionRequired	Minimum Version Required
Cluster Names Identical	ClusterNamesIdentical	Cluster Names Identical
Kicked	Kicked	Kicked
Proxy Not Trusted	ProxyNotTrusted	Proxy Not Trusted
Proxy Required	ProxyRequired	Proxy Required