Fixed window strategy

The Fixed window strategy restricts API request volume within a predefined time window. When request volume reaches the maximum limit within a specified timeframe, LLM Gateway blocks subsequent requests until the window resets.

This strategy defines a maximum request threshold (max) permitted within a configured interval. Setting a duration value (such as 24 hours) determines the counter reset frequency.

Grouping by specific headers (such as x-lunar-consumer-tag) applies targeted limits per user or subscription tier. For example, a fixed-window quota assigned to endpoint api.website.com/ permits 10,000 requests per month.

The following configuration example defines a monthly fixed-window quota:

/etc/lunar-proxy/quotas/{fileName}.yaml

quotas:
  - id: FixedWindowQuota # Unique identifier for the quota
    filter: # Define filter conditions for this quota
      url: api.website.com/* # URL pattern to apply the quota
    strategy:
      fixed_window:
        max: 10000 # Maximum requests allowed within the window
        interval: 1 # Window duration
        interval_unit: month # Unit of time for the interval (second/minute/hour/day/month)
        monthly_renewal:
          day: 1
          hour: 0
          minute: 0
          timezone: UTC # Optional: Monthly renewal configuration