Rate Limiting

RouteMQ includes advanced rate limiting middleware with multiple strategies and Redis backend support.

Topics

• Basic Rate Limiting - Simple rate limiting setup

• Rate Limiting Strategies - Different algorithms and approaches

• Topic-Specific Limits - Custom limits per topic pattern

• Client-Based Limiting - Rate limiting per client

• Advanced Features - Whitelisting, custom messages, fallbacks

Quick Overview

from app.middleware.rate_limit import RateLimitMiddleware

# Basic rate limiting - 100 requests per minute
rate_limit = RateLimitMiddleware(
    max_requests=100,
    window_seconds=60,
    strategy="sliding_window"
)

# Apply to routes
router.on("api/{endpoint}", Controller.handle, middleware=[rate_limit])

Rate Limiting Strategies

1. Sliding Window (Most Accurate)

Uses Redis sorted sets for precision:

sliding_window = RateLimitMiddleware(
    max_requests=100,
    window_seconds=60,
    strategy="sliding_window"
)

2. Fixed Window (Simple)

Resets at window boundaries:

fixed_window = RateLimitMiddleware(
    max_requests=100,
    window_seconds=60,
    strategy="fixed_window"
)

3. Token Bucket (Allows Bursts)

Allows burst traffic:

token_bucket = RateLimitMiddleware(
    max_requests=100,
    window_seconds=60,
    strategy="token_bucket",
    burst_allowance=50  # Allow up to 150 requests in bursts
)

Advanced Rate Limiting

Topic-Specific Limits

from app.middleware.rate_limit import TopicRateLimitMiddleware

topic_rate_limit = TopicRateLimitMiddleware(
    topic_limits={
        "sensors/batch/*": {"max_requests": 1000, "window_seconds": 60},
        "sensors/temperature/*": {"max_requests": 100, "window_seconds": 60},
        "devices/control/*": {"max_requests": 10, "window_seconds": 60},
    },
    default_limit={"max_requests": 50, "window_seconds": 60}
)

Client-Based Limits

from app.middleware.rate_limit import ClientRateLimitMiddleware

client_rate_limit = ClientRateLimitMiddleware(
    max_requests=50,
    window_seconds=60,
    client_id_field="client_id",
    strategy="sliding_window"
)

Advanced Features

advanced_rate_limit = RateLimitMiddleware(
    max_requests=100,
    window_seconds=60,
    strategy="sliding_window",
    whitelist=["admin/*", "emergency/*"],  # Bypass rate limiting
    custom_error_message="Too many requests. Please slow down.",
    fallback_enabled=True  # Use memory if Redis is down
)

Next Steps

• Basic Rate Limiting - Get started with rate limiting

• Strategies - Choose the right algorithm

• Redis Integration - Redis-powered rate limiting