3e7eddc074
This commit implements comprehensive production hardening across multiple layers to prepare StemeDB for enterprise pilot deployments: ## API Layer - Add rate limiting middleware with configurable limits per endpoint - Enhance error handling with detailed context and proper HTTP status codes - Add security hardening tests for input validation and boundary conditions - Create store_helpers module for defensive storage access patterns ## Storage & WAL - Optimize group commit batching for higher throughput - Add defensive error handling in hybrid backend with proper fallbacks - Enhance WAL journal durability guarantees with fsync validation - Improve index store query performance with better caching ## Operations & Deployment - Add comprehensive operations documentation (deployment, monitoring, DR) - Create systemd units for backup, WAL archival, and verification - Add monitoring configs (Prometheus alerts, metrics exporters) - Implement backup/restore scripts with verification and S3 archival - Add DR drill automation and runbook procedures - Create load balancer configs (nginx, envoy) with health checks ## Documentation - Update CLAUDE.md with operations and troubleshooting guides - Expand roadmap with production readiness milestones - Add pilot success criteria and deployment reference architecture - Document TLS setup, monitoring integration, and incident response ## Configuration - Add .env.example with all required environment variables - Document resource sizing for different deployment scales - Add configuration examples for various deployment topologies This positions StemeDB for successful enterprise pilots with proper operational discipline, monitoring, backup/DR, and security hardening. Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
237 lines
13 KiB
Plaintext
237 lines
13 KiB
Plaintext
# Three-Node Cluster Architecture Diagram
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## High-Level Topology
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```
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┌──────────────────────────────────────────────────────────────────────┐
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│ Client Layer │
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│ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │
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│ │ Agents │ │ Dashboard │ │ CLI Tools │ │
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│ └──────┬───────┘ └──────┬───────┘ └──────┬───────┘ │
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│ │ │ │ │
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│ └──────────────────┴──────────────────┘ │
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│ │ │
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│ │ HTTPS (443) │
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│ ▼ │
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└──────────────────────────────────────────────────────────────────────┘
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┌──────────────────────────────────────────────────────────────────────┐
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│ Load Balancer Layer │
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│ ┌─────────────────────────────────────────────────────────────────┐ │
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│ │ Nginx / Envoy / AWS ALB │ │
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│ │ • Round-robin distribution │ │
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│ │ • Health checks (5s interval) │ │
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│ │ • TLS termination │ │
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│ │ • Removes failed nodes automatically │ │
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│ └────────────┬──────────────┬──────────────┬─────────────────────┘ │
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│ │ │ │ HTTP (18180) │
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│ ▼ ▼ ▼ │
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└──────────────────────────────────────────────────────────────────────┘
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┌──────────────────────────────────────────────────────────────────────┐
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│ StemeDB Cluster Nodes │
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│ │
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│ ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │
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│ │ Node 1 │ │ Node 2 │ │ Node 3 │ │
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│ │ 10.0.1.51 │ │ 10.0.1.52 │ │ 10.0.1.53 │ │
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│ │ │ │ │ │ │ │
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│ │ stemedb-api │ │ stemedb-api │ │ stemedb-api │ │
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│ │ :18180 (API) │ │ :18180 (API) │ │ :18180 (API) │ │
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│ │ :18181 (Gate) │ │ :18181 (Gate) │ │ :18181 (Gate) │ │
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│ │ :18182 (RPC) │ │ :18182 (RPC) │ │ :18182 (RPC) │ │
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│ │ :18183 (SWIM) │ │ :18183 (SWIM) │ │ :18183 (SWIM) │ │
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│ │ │ │ │ │ │ │
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│ │ /data/wal/ │ │ /data/wal/ │ │ /data/wal/ │ │
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│ │ /data/db/ │ │ /data/db/ │ │ /data/db/ │ │
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│ └────────┬────────┘ └────────┬────────┘ └────────┬────────┘ │
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│ │ │ │ │
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│ └────────────────────┴────────────────────┘ │
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│ │ │
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│ SWIM Gossip + gRPC Replication │
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│ (UDP 18183 + TCP 18182) │
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│ Replication Factor: 2 │
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└──────────────────────────────────────────────────────────────────────┘
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```
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## Inter-Node Communication
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```
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Node 1 ◀──────────────────────────────────────────────────▶ Node 2
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│ │
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│ SWIM Gossip (UDP 18183) │
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│ • Membership: "Node 2 is UP" │
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│ • Failure detection: ping/ack │
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│ • Frequency: every 1 second │
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│ │
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│ gRPC Replication (TCP 18182) │
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│ • Push assertions: "Assert X written to Node 1" │
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│ • Pull sync: Merkle tree comparison │
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│ • Frequency: continuous │
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│ │
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│ │
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▼ ▼
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◀───────────────────────────────────────────────────────────▶
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Node 3
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(Same protocol with Node 1 & 2)
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```
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## Write Path (Replication Factor 2)
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```
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Client submits assertion
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│
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▼
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Load Balancer (routes to Node 1)
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│
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▼
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┌───────────────────────────────────────┐
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│ Node 1 (Coordinator) │
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│ │
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│ 1. Validate assertion │
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│ 2. Write to local WAL (fsync) │
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│ 3. Return 201 Created to client │
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│ 4. Async replicate to Node 2 │
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│ (background, no blocking) │
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└───────────────┬───────────────────────┘
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│
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│ gRPC (async)
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▼
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┌───────────────────┐
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│ Node 2 (Replica) │
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│ 1. Receive assert│
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│ 2. Write to WAL │
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│ 3. ACK to Node 1 │
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└───────────────────┘
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(Node 3 may also receive replica
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depending on hash-based shard assignment)
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```
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## Read Path (Eventually Consistent)
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```
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Client queries concept_path: "drug/aspirin/safety"
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│
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▼
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Load Balancer (routes to any node, e.g., Node 2)
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│
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▼
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┌───────────────────────────────────────┐
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│ Node 2 (Query Handler) │
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│ │
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│ 1. Check local KV store │
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│ 2. Apply lens (RecencyLens) │
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│ 3. Resolve conflicts (CRDTs) │
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│ 4. Return result to client │
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│ │
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│ No coordination with other nodes! │
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└───────────────────────────────────────┘
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│
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▼
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Client receives result (may be slightly stale if replication lag)
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```
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## Failure Scenario: Node 2 Down
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```
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Initial State (All UP):
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┌────────┐ ┌────────┐ ┌────────┐
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│ Node 1 │ │ Node 2 │ │ Node 3 │
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│ UP │ │ UP │ │ UP │
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└───┬────┘ └───┬────┘ └───┬────┘
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│ │ │
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└───────────┴───────────┘
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SWIM: All healthy
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Node 2 Failure:
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┌────────┐ ┌────────┐ ┌────────┐
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│ Node 1 │ │ Node 2 │ │ Node 3 │
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│ UP │ │ ❌ DOWN│ │ UP │
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└───┬────┘ └────────┘ └───┬────┘
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│ │
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└───────────────────────┘
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SWIM: Node 2 detected as DOWN
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Load Balancer: Health check fails, routes to Node 1 & 3
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Replication: Factor 2 maintained (data on Node 1 & 3)
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Recovery (Automatic):
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┌────────┐ ┌────────┐
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│ Node 1 │ │ Node 3 │
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│ UP │──────────────│ UP │
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└────────┘ └────────┘
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Cluster continues operating
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No data loss (replicated)
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No manual intervention
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RTO: <1 minute (automatic)
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RPO: 0 (no data loss)
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```
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## Merkle Sync (Convergence)
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```
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Node 1 Node 2
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┌──────────────┐ ┌──────────────┐
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│ Merkle Tree │ │ Merkle Tree │
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│ Root: ABC123│◀───────────────│ Root: DEF456│
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│ │ Compare roots │ │
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│ /drug/ │ (differ!) │ /drug/ │
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│ /treatment/ │────────────────▶│ /treatment/ │
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└──────────────┘ └──────────────┘
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│ │
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│ Descend tree, find diffs │
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▼ ▼
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Node 1 has: Node 2 has:
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- Assert X (missing on Node 2) - Assert Y (missing on Node 1)
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- Assert Z (both have) - Assert Z (both have)
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│ │
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▼ ▼
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Exchange missing assertions
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│ │
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▼ ▼
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Both nodes now have: X, Y, Z
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Root hash: GHI789 (same!)
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Convergence achieved.
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```
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## Cluster Health Monitoring
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```
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┌─────────────────────────────────────────────────┐
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│ Prometheus │
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│ Scrapes all 3 nodes every 15s │
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│ │
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│ Metrics: │
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│ - up{node="node1"} = 1 │
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│ - up{node="node2"} = 1 │
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│ - up{node="node3"} = 1 │
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│ - replication_lag_seconds{node="node2"} = 0.5 │
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│ - stemedb_query_latency_seconds{node="node1"} │
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└─────────────────┬───────────────────────────────┘
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│
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▼
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┌─────────────────┐
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│ Grafana │
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│ Dashboard │
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│ • Cluster map │
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│ • Latency p99 │
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│ • Repl lag │
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└─────────────────┘
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```
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## Key Characteristics
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- **High Availability:** Survives 1 node failure (99.9% uptime)
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- **Replication:** Factor 2 (each assertion on 2 nodes)
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- **Consistency:** Eventual (CRDTs + Merkle sync)
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- **Recovery:** Automatic (<5 minute RTO)
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- **Capacity:** <100K assertions, <1K queries/sec
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- **Cost:** ~$425/month (AWS t3.xlarge × 3)
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- **Use Case:** Production deployments, enterprise pilots
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✅ RECOMMENDED FOR PRODUCTION
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