Enum ProtocolErrorKind 

#[non_exhaustive]
pub enum ProtocolErrorKind {
    TruncatedFrame,
    CrcMismatch,
    UnknownApiVersion,
    InvalidLength,
    InvalidUtf8,
    UnsupportedMagic,
    InvalidValue,
    Malformed,
    Other,
}

Structured classification of KrafkaError::Protocol errors.

The Kafka wire protocol surfaces many distinct failure modes (truncated frames, CRC mismatches, version negotiation failures, oversized arrays, etc.) that callers may want to distinguish without substring-matching the error message. ProtocolErrorKind exposes the classification as a typed enum while keeping the human-readable detail on the accompanying message.

Kinds are coarse on purpose — they reflect retry/fail decisions rather than every possible broker-returned condition. Retriability is exposed via ProtocolErrorKind::is_retriable.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

TruncatedFrame

Buffer exhausted before a complete frame, field, or record could be read.

Usually indicates a short read on the wire or a truncated response body. Retriable: the request may succeed on a fresh connection.

CrcMismatch

Record batch CRC32C did not match the computed checksum.

Indicates on-wire corruption. Retriable.

UnknownApiVersion

No mutually supported API version, or the broker does not advertise the required API at all.

Not retriable — reflects a permanent client/broker version mismatch.

InvalidLength

An encoded length exceeds the protocol maximum (i32::MAX, u32::MAX, i16::MAX for KafkaString, etc.) or the configured safety cap (MAX_DECODE_ARRAY_LEN, MAX_RECORD_HEADERS).

Not retriable — indicates a malformed response or a misconfigured cap.

InvalidUtf8

Bytes decoded as a UTF-8 string were not valid UTF-8.

Not retriable.

UnsupportedMagic

Record batch magic byte is not a supported version (only 2 is accepted today).

Not retriable.

InvalidValue

A field value was outside its allowed range or encoded incorrectly (negative record count, bad enum discriminant, unknown header version, malformed varint, etc.).

Not retriable.

Malformed

The response was structurally malformed in a way that does not fit the other variants (unexpected partition in a response, missing required field, etc.).

Retriable — often transient and resolves after a metadata refresh or reconnection.

Other

Catch-all for protocol errors not otherwise classified.

Not retriable by default; callers should inspect the message.

Implementations

impl ProtocolErrorKind

pub fn is_retriable(self) -> bool

Returns true if this protocol error kind is typically transient and safe to retry after a reconnect or metadata refresh.

Trait Implementations

impl Clone for ProtocolErrorKind

fn clone(&self) -> ProtocolErrorKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ProtocolErrorKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for ProtocolErrorKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ProtocolErrorKind

fn eq(&self, other: &ProtocolErrorKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ProtocolErrorKind

impl Eq for ProtocolErrorKind

impl StructuralPartialEq for ProtocolErrorKind