krabka_metadata/group_version.rs
1//! KIP-848 `group.version` feature-level constants.
2//!
3//! It is a plain integer feature with no `X.Y-IVn` string table: level 0 means
4//! classic consumer groups only, and level 1 means next-gen (KIP-848) protocol
5//! GA. The range and the metadata.version bootstrap-default threshold are
6//! pinned against the cp-kafka 4.0 `GroupVersion` enum, verified empirically
7//! 2026-05-30.
8
9/// KIP-848 feature name.
10pub const GROUP_VERSION_FEATURE: &str = "group.version";
11
12/// Minimum supported level: classic-only.
13pub const GROUP_VERSION_MIN: i16 = 0;
14/// Maximum supported level: next-gen (KIP-848) GA.
15pub const GROUP_VERSION_MAX: i16 = 1;
16
17/// `group.version=1` is the bootstrap default once the formatted
18/// metadata.version is at least this level (4.0-IV0 = 22).
19///
20/// This is a bootstrap-default input only. Kafka declares no hard
21/// `UpdateFeatures` dependency for group.version.
22pub const GROUP_VERSION_GA_METADATA_LEVEL: i16 = 22;