Single Zone Deployment

%% Single-zone deployment — first-deployment "Small multi-node" production %% profile (the M4 data plane plus the M5 trust fabric; the ★ Step-2 release %% point is M8 — proposal 0013). %% Diagrams as code. Render with any Mermaid renderer. %% See 07-deployment-view.md (§7.4) and m4-first-deployment-blueprint.md. %% Shape shown: full-strength RS(6,3) — 9 D servers, one fragment per server, %% spread across 3 failure domains. The minimum-honest profile (6 D servers, %% ~2 fragments/domain, single-fault tolerance) is the same shape with fewer %% D servers; see the blueprint's sizing cheat-sheet. graph TB client(["S3 client / application"]) subgraph zone["Single zone — one site &nbsp;(no cross-zone replication — that is M9)"] subgraph access["Stateless — restartable, horizontally scalable"] gw["S3 gateway<br/>embeds client library<br/>(chunk · erasure-code · commit)"] cust["Custodian (leader-elected)<br/>GC · scrub · reconstruct · durability telemetry"] end subgraph metaplane["Metadata + coordination + trust — precious, separately replicated"] tikv["TiKV + PD<br/>3-node quorum (Raft)<br/>inodes · dirents · chunk-maps"] etcd["Coordination — etcd (L5)<br/>discovery · leader election · locks"] ca["Provider CA — step-ca (M5)<br/>short-lived mTLS certs, every internal dial<br/>(ADR-0036 · SPIRE reserved)"] end subgraph storage["D servers — RS(6,3): 9 fragments/chunk, 1 per server, any 3 lost survive"] fdA["Failure domain A<br/>rack / power / switch<br/>3 × D server"] fdB["Failure domain B<br/>3 × D server"] fdC["Failure domain C<br/>3 × D server"] end end backup[("Out-of-band backup<br/>independent of this cluster (§8.2)<br/>the only DR story until M9")] client -->|"S3 / HTTPS · SigV4"| gw gw -->|"metadata commit · gRPC (PD :2379 / TiKV :20160) · mTLS"| tikv gw -->|"bulk fragment I/O · gRPC :50051 · mTLS — spread 1 / domain"| fdA gw --> fdB gw --> fdC gw -.->|"discover D servers · etcd gRPC :2379"| etcd cust -->|"scrub · repair · reconstruct · gRPC :50051"| fdA cust --> fdB cust --> fdC cust -->|"find under-replicated · gRPC"| tikv cust -.->|"leader election · etcd gRPC :2379"| etcd fdA -.->|"register (id · endpoint · fd label) · etcd gRPC"| etcd gw -.->|"enroll · rotate short-lived certs (every role does)"| ca tikv -.->|"metadata export"| backup fdA -.->|"data export"| backup