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Technology Comparisons & Architectural Decisions
1. Database: MongoDB Time-Series vs InfluxDB vs TimescaleDB
| Comparison Factor | MongoDB 7 Time-Series (Used) | InfluxDB | TimescaleDB |
|---|---|---|---|
| Data Model | Unified Documents & Time-Series | Specialized TS Measurement | Relational SQL Hypertable |
| Operational Simplicity | Single DB for Users, Alerts & Vitals | Requires 2nd Database for Relational | Heavy PostgreSQL Ops |
| Compression Ratio | Columnar Snappy/Zstd | High Gorilla Compression | Good Compression |
| Ad-Hoc JSON Schema | High (Nested Device Sensors) | Poor for Complex JSON | Moderate |
- Why MongoDB: Allowed a single unified database deployment aboard the spacecraft habitat, eliminating the overhead of running both a time-series engine and a document store. [CONFIRM WITH DEVELOPER]
2. Event Streaming: Redis Streams vs Apache Kafka vs RabbitMQ
| Comparison Factor | Redis Streams (Used) | Apache Kafka | RabbitMQ |
|---|---|---|---|
| Resource Overhead | $<100MB$ RAM footprint | Heavy JVM ($>2GB$ RAM, ZooKeeper) | Moderate ($>300MB$) |
| Sub-millisecond Latency | Yes | Moderate | Yes |
| Delay Buffering | Native time-indexed stream reading | Partition offsets | Message TTL |
- Why Redis Streams: Minimal memory footprint ideal for embedded spacecraft servers while providing durable append-only log semantics.