Performance

Dataset: 28,014 packets, ~650 nodes, 2 observers
Hardware: ARM64 (MikroTik CCR2116), single-core Node.js

A/B Benchmark: v2.0.1 (before) vs v2.1.0 (after)

All times are averages over 3 runs. "Cached" = warm TTL cache hit.

Endpoint	v2.0.1	v2.1.0 (cold)	v2.1.0 (cached)	Speedup
Bulk Health	7,059 ms	3 ms	1 ms	7,059×
Node Analytics	381 ms	2 ms	1 ms	381×
Hash Sizes	353 ms	193 ms	1 ms	353×
Topology	685 ms	579 ms	2 ms	342×
RF Analytics	253 ms	235 ms	1 ms	253×
Channels	206 ms	77 ms	1 ms	206×
Node Health	195 ms	1 ms	1 ms	195×
Node Detail	133 ms	1 ms	1 ms	133×
Channel Analytics	95 ms	73 ms	2 ms	47×
Packets (grouped)	76 ms	33 ms	28 ms	2×
Stats	2 ms	1 ms	1 ms	2×
Nodes List	3 ms	2 ms	2 ms	1×
Observers	1 ms	8 ms	1 ms	1×

Architecture

Two-Layer Performance Stack

1. In-Memory Packet Store (packet-store.js)

   • All packets loaded from SQLite into RAM on startup (~28K packets = ~12MB)
   • Indexed by id, hash, observer, and node (Map-based O(1) lookup)
   • Ring buffer with configurable max memory (default 1GB, ~2.3M packets)
   • SQLite becomes write-only for packets — reads never touch disk
   • New packets from MQTT written to both RAM + SQLite

2. TTL Cache (server.js)

   • Computed API responses cached with configurable TTLs (via config.json)
   • Smart invalidation: packet bursts only invalidate channels/observers; analytics expire by TTL only
   • Pre-warmed on startup: subpaths, RF, topology, channels, hash-sizes, bulk-health
   • Result: most API responses served in 1-2ms from cache

Key Optimizations

• Eliminated all LIKE '%pubkey%' queries: Every node-specific endpoint was doing full-table scans on the packets table via decoded_json LIKE '%pubkey%'. Replaced with O(1) pktStore.byNode Map lookups.
• Single-pass computations: Channels, analytics, and subpaths computed in one loop instead of multiple SQL queries.
• Client-side WebSocket prepend: New packets appended to the table without re-fetching the API.
• RF response compression: Server-side histograms + scatter downsampling (1MB → 15KB).
• Configurable everything: All TTLs, packet store limits, and thresholds in config.json.

What Didn't Work

• Background refresh (setInterval): Attempted to re-warm caches at 80% TTL. Blocked the event loop — Node.js is single-threaded. Response times went from 3ms to 1,200ms. Reverted immediately.
• Worker threads: structuredClone overhead of 416ms for 28K packets negated the compute savings. Only viable at 10× data growth or with SharedArrayBuffer (zero-copy).

Running the Benchmark

# Stop the production server first
supervisorctl stop meshcore-analyzer

# Run A/B benchmark (launches two servers: old v2.0.1 vs current)
./benchmark-ab.sh

# Restart production
supervisorctl start meshcore-analyzer