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geocoder_caching_and_fallback_strategies

🛢️ Implementing Caching and Fallback Strategies​

For high‑volume geocoding or reverse lookups, caching responses in Redis reduces API calls and costs. Configure Geocoder to use Redis and fall back between services:

# config/initializers/geocoder.rb
Geocoder.configure(
  timeout: 5,
  lookup: :google,
  api_key: ENV['GOOGLE_GEOCODING_API_KEY'],
  cache: Redis.new(url: ENV['REDIS_URL']),
  cache_prefix: 'geocoder:',
  use_https: true,
  always_raise: [Geocoder::OverQueryLimitError, Geocoder::RequestDenied],
  lookup_cache: {
    fallback: :nominatim,
    nominatim: {
      host: 'nominatim.openstreetmap.org',
      format: 'json'
    }
  }
)

With this setup, Geocoder will:

  1. Attempt the Google API and cache the result under geocoder:... in Redis.
  2. On quota errors or timeouts, automatically retry using OpenStreetMap’s Nominatim.

You can then safely call:

coords = Geocoder.coordinates('1600 Amphitheatre Parkway, Mountain View, CA')