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HydraCache 0.45.0

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@github-actions github-actions released this 13 Jul 15:55
· 1248 commits to main since this release
v0.45.0
d12be8c

HydraCache 0.45.0

0.45.0 adds the active-active multi-region slice: opt-in
bounded-staleness writes, conflict-free value types, WAN region links with
anti-entropy, region failover/DR primitives, capacity/autoscaler guardrails, and
geo observability with SLO alerts.

The release keeps the 0.43 single-authority behavior as the default. Active-active
must be acknowledged explicitly and does not claim cross-region linearizability,
distributed transactions, or automatic conflict resolution for arbitrary values.

Highlights

  • Added ActiveActiveConfig, ActiveActiveState, GeoWrite,
    HybridLogicalClock, and explicit acknowledgement for the weaker
    cross-region bounded-staleness contract.
  • Added CRDT value types: GCounter, PnCounter, OrSet, and
    LwwRegister, plus tombstone dominance checks so deletes are not
    resurrected by concurrent CRDT updates.
  • Added RegionLink, GeoBatch, idempotent batch application, WAN backpressure,
    PartitionDigest, anti-entropy diffing, and CRDT metadata GC confirmation.
  • Added region failover/DR helpers: conservative RegionStateDetector,
    promote_region_home, lower-epoch rejoin fencing, and generic
    RegionRestore<S> over the existing replicated value-store seam.
  • Added capacity/autoscaler guardrails: CapacitySignal,
    ScaleRecommendation, guarded AutoscalerIntent admission, zone/quorum/COMPAT
    validation, and helpers that keep scale-out nodes out of quorum until
    backfill completes.
  • Added GeoStatus, per-region/link health DTOs, staleness SLO evaluation,
    geo dashboard artifacts, geo alert rules, and runbook steps for staleness
    breaches, region failover, and disabling active-active safely.

Verification

Focused gates:

cargo test -p hydracache --locked active_active
cargo test -p hydracache --locked crdt
cargo test -p hydracache --locked region_link
cargo test -p hydracache --locked region_failover
cargo test -p hydracache --locked capacity_autoscale
cargo test -p hydracache-observability --locked geo_observability

Code quality gates used during implementation:

cargo fmt --all -- --check
cargo clippy -p hydracache --all-targets --all-features --locked -- -D warnings
cargo clippy -p hydracache-observability --all-targets --all-features --locked -- -D warnings

Scope Boundary

This is an assisted active-active library surface. Operators still own topology,
WAN transport deployment, region-down declarations, durable snapshots, and SLO
budgets. The new APIs make the bounded-staleness trade visible and testable; they
do not turn HydraCache into a DB proxy, CDC platform, or distributed transaction
coordinator.

Release Status

Published as 0.45.0 after the focused gates above, release-readiness metadata
check, package verification, and staged crates.io publication in dependency
order.

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