chore #353: upgrade tonic 0.12 → 0.13 to eliminate rand 0.8.5 transitive dependency

[JoshuaChi]

What Does This PR Do?

Upgrades tonic 0.12 → 0.13 to eliminate the rand 0.8.5 transitive
dependency that triggered security advisory RUSTSEC-2026-0097.

Type:

• Bug Fix (with test)

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Why Is This Needed?

tonic 0.12 pulls in tower 0.4, which depends on rand 0.8.5,
triggering RUSTSEC-2026-0097 (unsound ThreadRng aliasing under
custom logger). The advisory was previously suppressed via deny.toml
ignore. tonic 0.13 uses tower 0.5, which drops the rand dependency
entirely — this is the only clean fix.

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Checklist

Required:

• make test passes
• Commits squashed to 1-2 logical units

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Testing

How tested:

• cargo check --all-features passes with zero warnings
• cargo tree | grep "rand 0.8" returns empty
• cargo deny check advisories passes with RUSTSEC-2026-0097 ignore removed

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Does This Follow d-engine's Principles?

• Solves a real problem for most users (not just my edge case)
• Keeps implementation simple
• Doesn't bloat the API surface

---

Reviewer Notes

All source changes are mechanical:

• use tonic::async_trait → use async_trait::async_trait (41 files, tonic 0.13 removed this re-export)
• tls feature → tls-ring (tonic 0.13 split TLS backends)
• mut health_reporter → health_reporter (tonic-health 0.13 returns immutable)
• embedded-bench: pre-existing SmallRng/gen/Alphanumeric API bug fixed by upgrading rand 0.8 → 0.9

No logic changes. No API surface changes.

Estimated review complexity:

• Medium (< 300 lines)

Summary by CodeRabbit

• Chores
  • Bumped gRPC framework to 0.13 with updated TLS provider and related build deps.
  • Upgraded benchmark and build dependencies (including rand and tonic-build).
  • Removed an advisory ignore so security reports will now surface the previously-suppressed advisory.
• Refactor
  • Switched async trait macro imports to the dedicated async-trait crate for consistency.
• Bug Fixes / Improvements
  • Prevented bounded-channel backpressure during snapshot streaming by draining ACK receivers.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 28aeb778-ef56-4c69-bd94-191f25765514

📥 Commits

Reviewing files that changed from the base of the PR and between 5fe9c7e and 9d99e63.

⛔ Files ignored due to path filters (6)

• Cargo.lock is excluded by !**/*.lock
• d-engine-proto/src/generated/d_engine.client.rs is excluded by !**/generated/**
• d-engine-proto/src/generated/d_engine.server.cluster.rs is excluded by !**/generated/**
• d-engine-proto/src/generated/d_engine.server.election.rs is excluded by !**/generated/**
• d-engine-proto/src/generated/d_engine.server.replication.rs is excluded by !**/generated/**
• d-engine-proto/src/generated/d_engine.server.storage.rs is excluded by !**/generated/**

📒 Files selected for processing (48)

• Cargo.toml
• benches/embedded-bench/Cargo.toml
• benches/embedded-bench/src/main.rs
• d-engine-client/src/mock_rpc_service.rs
• d-engine-core/Cargo.toml
• d-engine-core/src/commit_handler/default_commit_handler.rs
• d-engine-core/src/commit_handler/mod.rs
• d-engine-core/src/election/election_handler.rs
• d-engine-core/src/election/mod.rs
• d-engine-core/src/membership.rs
• d-engine-core/src/network/mod.rs
• d-engine-core/src/purge/default_executor.rs
• d-engine-core/src/purge/mod.rs
• d-engine-core/src/raft_role/candidate_state.rs
• d-engine-core/src/raft_role/follower_state.rs
• d-engine-core/src/raft_role/leader_state.rs
• d-engine-core/src/raft_role/learner_state.rs
• d-engine-core/src/raft_role/role_state.rs
• d-engine-core/src/replication/mod.rs
• d-engine-core/src/replication/replication_handler.rs
• d-engine-core/src/state_machine_handler/default_state_machine_handler.rs
• d-engine-core/src/state_machine_handler/mod.rs
• d-engine-core/src/storage/buffered_raft_log.rs
• d-engine-core/src/storage/raft_log.rs
• d-engine-core/src/storage/state_machine.rs
• d-engine-core/src/storage/state_machine_test.rs
• d-engine-core/src/storage/storage_engine.rs
• d-engine-core/src/storage/storage_engine_test.rs
• d-engine-core/src/test_utils/mock/mock_rpc_service.rs
• d-engine-proto/Cargo.toml
• d-engine-server/Cargo.toml
• d-engine-server/src/membership/raft_membership.rs
• d-engine-server/src/network/grpc/grpc_transport.rs
• d-engine-server/src/network/grpc/mod.rs
• d-engine-server/src/network/health_checker.rs
• d-engine-server/src/network/health_monitor.rs
• d-engine-server/src/storage/adaptors/file/file_engine_test.rs
• d-engine-server/src/storage/adaptors/file/file_state_machine.rs
• d-engine-server/src/storage/adaptors/file/file_state_machine_test.rs
• d-engine-server/src/storage/adaptors/file/file_storage_engine.rs
• d-engine-server/src/storage/adaptors/file/file_storage_engine_test.rs
• d-engine-server/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
• d-engine-server/src/storage/adaptors/rocksdb/rocksdb_state_machine_test.rs
• d-engine-server/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
• d-engine-server/src/storage/adaptors/rocksdb/rocksdb_storage_engine_test.rs
• d-engine-server/src/storage/adaptors/rocksdb/rocksdb_unified_engine_test.rs
• d-engine-server/src/test_utils/mock/mock_rpc_service.rs
• deny.toml

📝 Walkthrough

Walkthrough

Upgrades gRPC-related workspace dependencies to 0.13 (tonic, tonic-health, tonic-build), bumps rand in benches, replaces use tonic::async_trait with use async_trait::async_trait across many modules, adjusts health_reporter mutability bindings, adds background draining of snapshot ACK receivers in follower/learner, and removes an advisory ignore in deny.toml.

Changes

Cohort / File(s)	Summary
Workspace deps & build Cargo.toml, d-engine-proto/Cargo.toml, d-engine-core/Cargo.toml, d-engine-server/Cargo.toml	Bumped tonic/tonic-health/tonic-build to 0.13 (changed tonic features: tls → tls-ring), and switched some tonic-health entries to workspace = true.
Benchmark deps & RNG logic benches/embedded-bench/Cargo.toml, benches/embedded-bench/src/main.rs	Upgraded rand 0.8 → 0.9; moved Alphanumeric import to rand::distr, switched RNG init from SmallRng::from_entropy() + rng.gen() to SmallRng::from_os_rng() + rng.random().
async_trait import migration d-engine-core/src/..., d-engine-server/src/... (many files, e.g., commit_handler/*, election/*, raft_role/*, storage/*, replication/*, state_machine_handler/*, network/*, tests, adaptors, etc.)	Replaced use tonic::async_trait; with use async_trait::async_trait; across modules so #[async_trait] resolves to the standalone crate.
Snapshot ACK handling (raft roles) d-engine-core/src/raft_role/follower_state.rs, .../learner_state.rs	Changed ACK channel handling: keep receiver (mut ack_rx) and spawn a background task that continuously drains ack_rx to avoid bounded-channel backpressure during InstallSnapshotChunk streaming.
Health reporter mutability d-engine-client/src/mock_rpc_service.rs, d-engine-core/src/test_utils/mock/mock_rpc_service.rs, d-engine-server/src/network/grpc/mod.rs, d-engine-server/src/test_utils/mock/mock_rpc_service.rs	Removed mut binding when destructuring health_reporter(); subsequent set_serving/set_not_serving calls unchanged.
Configuration cleanup deny.toml	Removed an advisory ignore entry for RUSTSEC-2026-0097 (rand/tower advisory).

Sequence Diagram(s)

sequenceDiagram
  participant Leader
  participant Follower as Follower/Learner
  participant SnapshotApplier as SnapshotApply
  participant AckDrain as ACK-Drain-Task

  Leader->>Follower: InstallSnapshotChunk (stream of chunks)
  Follower->>SnapshotApplier: apply_snapshot_stream_from_leader(chunk)
  SnapshotApplier-->>Follower: per-chunk result (await)
  Follower->>Leader: send ACK (ack_tx.try_send or send)
  Note right of Follower: spawn ACK-Drain-Task to continuously recv from ack_rx
  AckDrain->>Follower: drain ack_rx (prevent backpressure)
  Leader-->>Follower: continue streaming next chunk

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~30 minutes

Possibly related issues

• chore: upgrade tonic 0.12 → 0.13 to eliminate rand 0.8.5 transitive dependency #353: Implements the same tonic/tonic-health/tonic-build 0.12→0.13 upgrade and async_trait migration referenced by the issue.

Possibly related PRs

• fix #308: snapshot install success driven by apply result not transfer ACK #360: Touches snapshot ACK handling in raft roles; strongly related to the ACK-drain changes here.
• Feature/182 local client #183: Performs the same async_trait import migration and related dependency updates.
• feat #167: workspace structure #175: Modifies MockNode::mock_listener health_reporter binding similarly to this PR.

Poem

🐰 Hopped through crates with nimble paws,

tonic raised, and async trait applause.
ACKs drained gently, no backpressure fright,
Rand refreshed for a brighter night.
A rabbit cheers — the build takes flight! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 37.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main objective: upgrading tonic from 0.12 to 0.13 to eliminate a transitive rand 0.8.5 dependency that triggered a security advisory.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch chore/353-tonic-013

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[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
d-engine-core/src/raft_role/learner_state.rs	0.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!