HydraCache 0.48.0

HydraCache 0.48.0

0.48.0 adds the production deployment and security slice: a standalone
hydracache-server daemon, graceful upgrade model, mTLS posture checks,
certificate/key lifecycle seams, at-rest sealed artifacts, object-store backup
plus PITR restore, Docker/Kubernetes artifacts, Prometheus exporter, runbooks,
and overload admission control.

The release does not add an external client protocol, SDKs, Hibernate provider,
KMS ownership, or distributed transactions. It makes the correctness-proven grid
deployable and operable while keeping secrets, certificates, and infrastructure
policy operator-owned.

Highlights

• Added hydracache-server with validated server config, lifecycle state,
  health/readiness snapshots, graceful drain, and environment-driven TLS/backup
  settings.
• Added graceful upgrade primitives that require the replacement process to be
  ready before the old process drains and prove no in-flight request is dropped.
• Added cluster transport mTLS posture checks: required peer certificate,
  trusted CA, expiry, optional DNS boundary, and fail-loud non-loopback startup.
• Added at-rest security lifecycle primitives: AtRestKeyProvider,
  StaticAtRestKeyProvider, AtRestSealer, SealedArtifact, and certificate
  rotation windows.
• Added object-store backup and PITR restore helpers with versioned
  BackupManifest, object checksums, corruption detection, and restore-to-point.
• Added Dockerfile, Kubernetes StatefulSet/services/PDB, Helm chart, deployment
  guide, and fast deploy smoke tests with Docker/kind drills marked as nightly.
• Added Prometheus text exporter, registered metric drift tests, dashboard/alert
  artifacts, deploy/upgrade/DR/incident runbooks, and FIFO admission control with
  retryable backpressure.
• Added deterministic deployment recovery simulation for rolling upgrade,
  cert rotation, backup corruption, and PITR restore faults.

Verification

Focused gates:

cargo test -p hydracache-server --locked server_lifecycle
cargo test -p hydracache-server --locked graceful_upgrade
cargo test -p hydracache-cluster-transport-axum --locked tls
cargo test -p hydracache --locked security_lifecycle
cargo test -p hydracache --locked backup_restore
cargo test -p hydracache-server --locked deploy_smoke
cargo test -p hydracache-observability --locked exporter
cargo test -p hydracache --locked admission
cargo test -p hydracache-sim --locked upgrade_and_recovery

Implementation checks used during the release work:

cargo fmt --all
cargo test -p hydracache-server --locked server_lifecycle
cargo test -p hydracache-server --locked graceful_upgrade
cargo test -p hydracache-cluster-transport-axum --locked tls
cargo test -p hydracache --locked security_lifecycle
cargo test -p hydracache --locked backup_restore
cargo test -p hydracache-server --locked deploy_smoke
cargo test -p hydracache-observability --locked exporter
cargo test -p hydracache --locked admission
cargo test -p hydracache-sim --locked upgrade_and_recovery

Scope Boundary

This is a production deployment and operations release, not a new consistency or
transaction layer. HydraCache still does not own database transactions, KMS,
secret stores, cloud autoscalers, or global distributed transactions. Nightly
Docker/kind drills cover the heavier deployment path; fast gates keep the
operator contracts deterministic in CI.

Release Status

Implemented as the 0.48.0 release slice after the focused gates above. The
workspace version remains on the current published line until the explicit
publish step.