Simple script to migrate all Redis keys from one server (REDIS_ORIGIN_URL) to another (REDIS_DESTINATION_URL)

migrate_redis.rb

# NOTE: Don't get your two Redis URLs mixed up or you'll lose data!

require "redis"

redis1 = Redis.new(url: ENV.fetch("REDIS_ORIGIN_URL"))
redis2 = Redis.new(url: ENV.fetch("REDIS_DESTINATION_URL"))

# NOTE: Uncomment this if you want to clear out all Sidekiq stats from the ORIGIN(!) server
# redis1.pipelined do |pipeline|
#   redis1.keys("stat:processed:*").each do |key|
#     puts "Deleting #{key}"
#     pipeline.del(key)
#   end
# end
# 
# redis1.pipelined do |pipeline|
#   redis1.keys("stat:processed:*").each do |key|
#     puts "Deleting #{key}"
#     pipeline.del(key)
#   end
# end

# Clear all redis2 keys
redis2.flushdb

redis1.keys.each do |key|
  puts "Setting #{key}"
  puts "Type: #{redis1.type(key)}"

  case redis1.type(key)
  when "string"
    redis2.set(key, redis1.get(key))
  when "list"
    redis2.del(key)
    redis1.lrange(key, 0, -1).each do |value|
      redis2.rpush(key, value)
    end
  when "set"
    redis2.del(key)
    redis1.smembers(key).each do |value|
      redis2.sadd(key, value)
    end
  when "zset"
    redis2.del(key)
    redis1.zrange(key, 0, -1, with_scores: true).each do |value, score|
      redis2.zadd(key, score, value)
    end
  when "hash"
    redis2.del(key)
    redis1.hgetall(key).each do |field, value|
      redis2.hset(key, field, value)
    end
  end
end