Errors¶

natsio.errors ¶

Public exception hierarchy.

Every exception raised by natsio derives from NATSError. Where it helps except ergonomics, subtrees additionally mix in the matching builtin (e.g. TimeoutError is also a builtins.TimeoutError).

AuthenticationExpiredError ¶

AuthenticationExpiredError(
    description: str = "", *, fatal: bool = True
)

Bases: ServerError

Credentials expired while the connection was active.

AuthorizationViolationError ¶

AuthorizationViolationError(
    description: str = "", *, fatal: bool = True
)

Bases: ServerError

Credentials were rejected by the server.

BadHeadersError ¶

BadHeadersError(description: str = '')

Bases: NATSError

A header block or user-supplied header is malformed or unsafe to send.

ConfigError ¶

ConfigError(description: str = '')

Bases: NATSError, ValueError

Invalid client configuration.

ConnectionClosedError ¶

ConnectionClosedError(description: str = '')

Bases: NATSError, ConnectionError

The operation cannot proceed because the connection is closed.

DrainTimeoutError ¶

DrainTimeoutError(description: str = '')

Bases: TimeoutError

A drain did not finish within drain_timeout.

MaxControlLineExceededError ¶

MaxControlLineExceededError(description: str = '')

Bases: ParserError

A control line exceeded the configured maximum length.

MaxPayloadExceededError ¶

MaxPayloadExceededError(description: str = '')

Bases: ProtocolError

A message payload exceeded the maximum payload size.

MaxSubscriptionsExceededError ¶

MaxSubscriptionsExceededError(description: str = '')

Bases: ServerError

The account's subscription limit was hit. Non-fatal: the connection stays open.

MissingDependencyError ¶

MissingDependencyError(description: str = '')

Bases: NATSError, ImportError

An optional dependency is required for the requested feature.

NATSError ¶

NATSError(description: str = '')

Bases: Exception

Root of the natsio exception hierarchy.

NoReplySubjectError ¶

NoReplySubjectError(description: str = '')

Bases: NATSError

Attempted to respond to a message that carries no reply subject.

NoRespondersError ¶

NoRespondersError(description: str = '')

Bases: NATSError

No subscriber is listening on the requested subject (server status 503).

NoServersAvailableError ¶

NoServersAvailableError(description: str = '')

Bases: ConnectionClosedError

Every server in the pool is unreachable or exhausted its retry budget.

ParserError ¶

ParserError(description: str = '')

Bases: ProtocolError

Fatal framing/parsing failure.

A byte stream cannot be resynchronized mid-frame: after this is raised the parser refuses further use and the connection must be torn down.

PermissionsViolationError ¶

PermissionsViolationError(description: str = '')

Bases: ServerError

Publish/subscribe denied for a subject. Non-fatal: the connection stays open.

ProtocolError ¶

ProtocolError(description: str = '')

Bases: NATSError

The peer violated the NATS wire protocol.

ReconnectBufExceededError ¶

ReconnectBufExceededError(description: str = '')

Bases: NATSError

A publish issued while disconnected exceeded reconnect_buf_size.

Non-fatal: the connection stays alive and reconnect continues; only this publish is rejected. Raised immediately for every disconnected publish when buffering is disabled (reconnect_buf_size=-1).

ServerError ¶

ServerError(description: str = '', *, fatal: bool = True)

Bases: NATSError

An error reported by the server via -ERR.

SlowConsumerError ¶

SlowConsumerError(
    description: str = "",
    *,
    subject: str = "",
    sid: int = 0,
    dropped: int = 0,
)

Bases: NATSError

A subscription exceeded its pending limits; messages were dropped.

StaleConnectionError ¶

StaleConnectionError(
    description: str = "", *, fatal: bool = True
)

Bases: ServerError

The server (or ping monitoring) declared the connection stale.

SubscriptionClosedError ¶

SubscriptionClosedError(description: str = '')

Bases: NATSError

The subscription has been unsubscribed or drained.

TimeoutError ¶

TimeoutError(description: str = '')

Bases: NATSError, TimeoutError

An operation exceeded its deadline.

WebsocketError ¶

WebsocketError(description: str = '')

Bases: ProtocolError

A WebSocket (RFC 6455) handshake or framing violation.

Fatal like a framing error: a WebSocket stream cannot be resynchronized mid-frame, so the transport must be torn down.