How to fix ER_CON_COUNT_ERROR: Too many connections in Node.js

What this error means

Placeholder meaning for ER_CON_COUNT_ERROR: Too many connections. This error needs detailed documentation.

Typical symptoms

• Symptom 1
• Symptom 2
• Symptom 3

Common causes

1. Cause 1
2. Cause 2
3. Cause 3

How to fix "ER_CON_COUNT_ERROR: Too many connections"

Advanced notes

Related errors

• Error: EMFILE: too many open files, watch

  EMFILE: fs.watch() limit exceeded

  HIGH

• Error: Middleware next() called multiple times (next() invoked twice)

  Express middleware next() called multiple times

  HIGH

• Error: Worker failed to initialize (worker startup error)

  Worker failed to initialize in Node.js

  HIGH

Official resources & further reading

• 📚Node.js Official Documentation
• 📖
  MySQL max_connections System Variable(Official Docs)
• 🐙
  Too many connections issue in node-mysql2(GitHub)
• 📝
  Node.js MySQL: Too Many Connections Solutions
• 🐙
  Connection pooling not working as expected(GitHub)