mazacoin-explorer/TROUBLESHOOTING.md

Mazacoin Explorer - Troubleshooting Log

2026-03-07: Whitescreen Issue

Problem

Explorer showing blank white screen after initial flash of content.

Root Causes Found

1. Missing SSH in Docker container

   • Backend container (node:20-alpine) didn't include openssh-client
   • Fix: Added RUN apk add --no-cache openssh-client to Dockerfile

2. Sequential SSH calls (30+ second load time)

   • Original code fetched 10 blocks sequentially (~3 sec each = 30+ sec total)
   • Fix: Changed to parallel fetching with Promise.all()

3. SSH connection limit exceeded

   • Parallel fetching opened 10 simultaneous SSH connections
   • Windows SSH server rejected connections: "(SSH) Channel open failure"
   • Fix: Batched parallel requests (3 at a time) to stay under connection limit

Final Solution

// /root/Projects/mazacoin-explorer/backend/src/server.js
// Fetch blocks with limited concurrency (batches of 3)
const BATCH_SIZE = 3;
for (let i = 0; i < heights.length; i += BATCH_SIZE) {
  const batch = heights.slice(i, i + BATCH_SIZE);
  const batchResults = await Promise.all(batch.map(async (height) => {
    // fetch block...
  }));
  blocks.push(...batchResults.filter(b => b !== null));
}

Current Performance

• API response time: ~0.1 seconds (was 30-45 seconds)
• No SSH errors
• Backend healthy and responsive

Next Steps

• Rebuilding frontend container (no-cache) to ensure clean build
• Verify React app loads without JavaScript errors