Crate krabka_metadata 

Versioned metadata records and the immutable image they apply to.

krabka-metadata provides MetadataRecord, the versioned union of topic, partition, broker-registration, and topic-deletion records, and MetadataImage, an immutable snapshot of the cluster’s metadata.

Only MetadataImage::apply mutates the image, and the Raft state machine in krabka-raft calls that method. Everywhere else reads it through shared references and Arc clones.

Applying controller records

use krabka_metadata::{MetadataImage, MetadataRecord, TopicRecord};
use uuid::Uuid;

let mut image = MetadataImage::new(Uuid::new_v4());
let topic_id = Uuid::new_v4();

image.apply(&MetadataRecord::V1Topic(TopicRecord {
    name: "orders".into(),
    topic_id,
    partitions: 0,
    replication_factor: 3,
}));

let topic = image.topic("orders").expect("topic exists");
assert_eq!(topic.topic_id, topic_id);

Canonical quota entity keys

use krabka_metadata::canonicalize_entity;

let key = canonicalize_entity(vec![
    ("user".to_string(), Some("alice".to_string())),
    ("client-id".to_string(), Some("analytics".to_string())),
]);

assert_eq!(key[0].0, "client-id");
assert_eq!(key[1].0, "user");

Re-exports

pub use acl::AclEntry;

pub use acl::AclEntryFilter;

pub use acl::AclOperation;

pub use acl::PatternType;

pub use acl::PermissionType;

pub use acl::ResourceType;

pub use break_glass::BreakGlassAction;

pub use break_glass::BreakGlassApproval;

pub use break_glass::BreakGlassProposalRecord;

pub use kafka_record::KafkaRecordError;

pub use kafka_record::from_kafka_record;

pub use kafka_record::to_kafka_record;

pub use krabka_version::KrabkaVersion;

pub use krabka_version::PrivateRpc;

pub use krabka_version::private_rpc_version;

pub use kraft_translate::PRIVATE_RECORD_VERSION;

pub use kraft_translate::TranslateError;

pub use kraft_translate::from_kraft;

pub use kraft_translate::from_kraft_value;

pub use kraft_translate::to_kraft;

pub use kraft_translate::to_kraft_records;

pub use kraft_translate::to_kraft_values;

pub use write_freeze::TopicFreezeRecord;

pub use krabka_voters as voters;

Modules

acl

Wire-stable ACL types replicated through the raft quorum with MetadataRecord::V1AccessControlEntry and V1DeleteAccessControlEntry.

break_glass

Break-glass proposal records, replicated through the raft quorum with MetadataRecord::V1BreakGlassProposal and V1DeleteBreakGlassProposal.

directory_id

KIP-858 reserved log-directory ids, transcribed from Kafka’s org.apache.kafka.common.DirectoryId.

group_version

KIP-848 group.version feature-level constants.

kafka_record

Bridge between MetadataRecord and a Kafka [Record] whose value is the wincode encoding of the record.

krabka_version

The krabka-owned krabka.version feature (KIP-584).

kraft_translate

Translate Krabka’s internal MetadataRecord currency to and from the KIP-631 [KraftMetadataRecord] wire shape, so the controller log and snapshots are genuinely KIP-631-framed.

metadata_version

KIP-778 metadata.version feature-level model.

transaction_version

KIP-890 transaction.version feature-level constants, matching Kafka’s TransactionVersion, which defines TV_0 to TV_2 only.

write_freeze

Topic write-freeze registry entries, replicated through the raft quorum with MetadataRecord::V1TopicFreeze.

Structs

BrokerConfigRecord

Per-broker configuration key/value pair. Some(value) = set; None = delete.

BrokerEndpoint

A single named listener endpoint advertised by a broker.

BrokerRegistrationChangeRecord

Kafka’s BrokerRegistrationChangeRecord (metadata apiKey 17): a delta on the registration of one broker.

BrokerRegistrationRecord

ClientMetricsConfigRecord

KIP-714 client-metrics subscription config.

ClientQuotaRecord

ControllerRegistrationRecord

KIP-919 controller registration persisted in the metadata log.

DelegationToken

In-memory image type for a single delegation token (KIP-48). Mirrors DelegationTokenRecord without any tombstone concerns. The apply path handles tombstones as removals.

DelegationTokenRecord

A single delegation token’s authoritative state (KIP-48).

DeleteDelegationTokenRecord

Tombstone record that removes a delegation token (KIP-48) from the image. The ExpireDelegationToken handlers and the background expiry sweep emit it.

DeleteScramCredentialRecord

DeleteTopicRecord

FeatureLevelRecord

KIP-584 finalized feature level.

FeaturesEpochRecord

Snapshot-only carrier for the KIP-584 finalized-features epoch.

GroupConfigRecord

KIP-1071 dynamic configuration for one group resource. Each record is the authoritative override map for group_id; an empty map clears the resource.

KRaftVersionRange

Supported kraft.version range for a voter. The range is inclusive.

KRaftVersionRecord

KIP-853: finalizes the cluster-wide kraft.version feature level.

LeaderEpoch

A partition leader epoch. KIP-320 wire type: int32.

MetadataImage

NodeId

A broker, node, replica, or controller identifier.

PartitionDirAssignmentRecord

KIP-858 directory-assignment delta.

PartitionElrRecord

KIP-966 eligible-leader state for one partition. Empty vectors clear it.

PartitionOffsetAdvanceRecord

Diskless offset-sequencer delta: advance a partition’s committed next-offset by count.

PartitionRecord

PartitionRecoveryRecord

PartitionUpdateRecord

A Kafka PartitionChangeRecord can carry assignment, ELR, and recovery changes together. This record preserves that atomic update on replay.

ProducerIdsRecord

Durable controller state for cluster-wide producer-ID block allocation. next_producer_id is the first ID not covered by any committed block.

QuotaEntity

ScramCredentialRecord

TopicConfigRecord

Mutable topic configuration overrides.

TopicRecord

UnregisterBrokerRecord

KIP-919 / UnregisterBroker (api_key 64), Kafka’s UnregisterBrokerRecord (metadata apiKey 1).

UnregisterControllerRecord

KIP-1312 UnregisterController (api_key 94), Kafka trunk’s UnregisterControllerRecord (metadata apiKey 29).

Voter

One voter’s full identity.

VoterEndpoint

A single listener endpoint advertised by a voter.

VoterSet

The authoritative voter set, ordered by node id.

VotersRecord

KIP-853: full snapshot of the controller voter set.

Enums

FencingChange

A change to the fencing state of a broker registration, as Kafka’s BrokerRegistrationFencingChange encodes it in BrokerRegistrationChangeRecord.Fenced.

LeaderRecoveryState

KIP-704 state of an uncleanly elected leader.

MetadataError

MetadataRecord

ThrottleKind

Selects which broker byte-rate config key to read.

Constants

DEFAULT_BROKER_CONFIG_NODE_ID

Internal identity for Kafka’s cluster-wide default broker-config resource. Broker IDs are non-negative signed 32-bit integers on the Kafka wire, so this value cannot collide with a real broker.

Traits

Feature

One versioned cluster feature (KIP-584).

Functions

bootstrap_feature_records

KIP-584/1022 bootstrap: one V1FeatureLevel record per registered feature at its per-release default, derived from bootstrap_mv, the bootstrap metadata.version level.

bootstrap_feature_records_with_overrides

KIP-1022 krabka format seeding: one V1FeatureLevel record per registered feature.

canonicalize_entity

feature

Look up a registered feature by name.

feature_registry

All features this broker supports finalizing. Single source of truth.

is_supported_level

True if level is within the registered feature’s supported range. false for an unknown feature (nothing supports that level).

supported_feature_ranges

Supported feature ranges advertised by a Krabka broker or controller when it registers with the KRaft controller.

validate_feature_dependencies

KIP-1022 dependency validation for a fully-resolved feature→level map, as seeded by krabka format.

Type Aliases

EntityKey