rails redis kredis caching

Rails Kredis for higher-level Redis operations

Maya Patel Jan 2026

2 tabs

class Post < ApplicationRecord
  # View counter - increments without hitting the database
  kredis_counter :view_count, expires_in: 1.day

  # Recent viewers list - stores last 10 viewer IDs
  kredis_unique_list :recent_viewers, limit: 10

  # Flag for featured status
  kredis_flag :featured

  # Hash for cached statistics
  kredis_hash :statistics

  def increment_views!(user_id)
    view_count.increment
    recent_viewers.prepend(user_id)

    # Update database counter periodically
    if view_count.value % 10 == 0
      update_column(:views, views + 10)
    end
  end

  def viewer_count
    recent_viewers.elements.size
  end

  def stats
    statistics.entries.presence || compute_and_cache_stats
  end

  private

  def compute_and_cache_stats
    stats = {
      'likes' => likes.count,
      'comments' => comments.count,
      'shares' => shares.count
    }
    statistics.update(stats)
    stats
  end
end

module Api
  module V1
    class PostsController < ApplicationController
      def show
        post = Post.find(params[:id])

        # Increment view count
        post.increment_views!(current_user&.id || "anon_#{request.remote_ip}")

        render json: post.as_json.merge(
          view_count: post.view_count.value,
          viewer_count: post.viewer_count,
          statistics: post.stats
        )
      end
    end
  end
end

2 files · ruby Explain with highlit

Kredis provides typed Redis structures as Active Model attributes, simplifying common patterns like counters, flags, and lists. Instead of raw Redis commands, I define kredis accessors on models that handle serialization automatically. Counters track metrics like view counts, lists manage ordered collections, and flags store boolean states. Kredis uses connection pooling and handles expiration seamlessly. For real-time features, I combine Kredis with Action Cable—store online users in a Redis set, broadcast presence updates. The library integrates with Rails' encrypted credentials for sensitive data. This abstraction makes Redis feel like native Rails, improving developer productivity while maintaining performance.