EMQX Rate Limiting Not Working

In this tutorial, you'll learn about EMQX Rate Limiting Not Working. We cover key concepts, practical examples, and best practices.

The Problem

Client connection or message rate limiting does not prevent excessive traffic.

Quick Fix

Wrong

# No rate limiting configured — all traffic allowed

Broker overwhelmed by excessive connections or messages.

Right

# EMQX rate limiting config (emqx.conf)
# zone.default.rate_limit {
#   max_conn_rate = 1000  # Max connections per second
#   messages_per_second = 10000
#   bytes_per_second = 1048576  # 1 MB/s
# }

# Check current rate limit stats
curl -u admin:public http://localhost:18083/api/v5/rate_limit

# Set via API
curl -u admin:public -X PUT http://localhost:18083/api/v5/rate_limit \
  -d '{'max_conn_rate':500,'messages_per_second':5000}'

Rate limits enforced. Clients exceeding limits get connection refused or throttled.

Prevention

Rate limiting protects the broker from DoS and misconfigured clients. Configure per-zone limits (internal vs external). Monitor rate limit hit counters. Set reasonable limits based on expected traffic. Use MQTT 5.0 reason codes for throttle feedback.

DodaTech engineers apply these same patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro for production IoT reliability.

FAQ