Step 9 — Rollout Plan

Migrasi IPC privileged berisiko: salah konfigurasi = service tidak bisa diperintah, atau worse — exposed ke proses non-trusted.

9.1 Strategi: dual-stack dengan feature flag

Selama 1–2 release cycle, jalankan dua-duanya paralel.

Shared/FeatureFlags.cs

public static class FeatureFlags
{
    // Toggle via registry, env var, atau config file
    public static bool UseStreamJsonRpc =>
        Environment.GetEnvironmentVariable("HERMES_USE_RPC") == "1";
}

Di service startup:

if (FeatureFlags.UseStreamJsonRpc)
    await rpcHost.StartAsync();
else
    _ = legacyIpc.StartIpcLoopAsync();

Di UI:

if (FeatureFlags.UseStreamJsonRpc)
    await HermesRpcClient.Instance.StartAsync();
else
    _ = legacyIpcReceiver.StartListening();

9.2 Tahap rollout

Tahap	Audiens	Kriteria pindah ke tahap berikutnya
0. Dev	Engineer aktif	Unit + integration test green di Windows
1. Internal alpha	Tim Hermes (10 user)	1 minggu tanpa regresi; metric: 0 disconnect tak terjelaskan, < 100ms p95 RPC
2. Closed beta	50 user pilihan (flag ON via installer override)	2 minggu; bug rate ≤ legacy
3. GA opt-in	Semua user, flag default OFF, dapat di-toggle	4 minggu, ≥ 30% opt-in tanpa bug critical
4. GA default ON	Default ON, legacy masih bisa di-toggle	4 minggu
5. Legacy removed	Semua	Tidak ada bug report yang butuh legacy

9.3 Observability selama rollout

Tambah metrics:

• hermes_rpc_connect_duration_ms (histogram)
• hermes_rpc_call_duration_ms{method} (histogram)
• hermes_rpc_call_total{method,result} (counter: success / fail / cancelled)
• hermes_rpc_disconnects_total{reason} (counter)
• hermes_rpc_reconnects_total (counter)
• hermes_rpc_event_pushed_total{event} (counter)

Log struktural dengan correlation id (gunakan Activity / System.Diagnostics.ActivitySource).

9.4 Rollback plan

Skenario kegagalan & action:

Gejala	Action
UI tidak bisa connect	Set HERMES_USE_RPC=0 via remote config; restart UI
Service crash terus-menerus saat RPC active	Toggle env var di service, restart Windows Service
Bug security ditemukan di transport	Hotfix release; rollback flag ke OFF
Performance regression	Profile dulu, jangan rollback otomatis

Selama feature flag masih ada, rollback < 5 menit.

9.5 Cleanup setelah GA stabil

Setelah tahap 5:

• Hapus HermesNetwork/Conn/IpcComService.cs (141 baris)
• Hapus HermesServices/HermesServiceEngine/Conn/IpcComService.cs (456 baris)
• Hapus HermesNetwork/Models/IpcMessageCommand.cs & IpcMessageResult.cs (kalau tidak dipakai event bus lagi)
• Hapus konstanta IpcConst yang hanya untuk routing
• Hapus FeatureFlags.UseStreamJsonRpc & semua branch if (flag)
• Update dokumentasi internal & onboarding

9.6 Komunikasi

• Release notes: "Improved IPC reliability with industry-standard JSON-RPC framing. No user action required."
• Internal docs: link ke guide ini di Confluence/Notion tim.
• Support team brief: cara baca log baru, cara toggle flag manual.

Checklist final

• Feature flag wired di kedua sisi
• Metrics + struktur log siap
• Rollback drill di staging — < 5 menit
• Release notes draft
• Support team trained
• Go/no-go meeting per tahap