class ActiveSupport::Cache::RedisCacheStore

def increment(name, amount = 1, options = nil)

Failsafe: Raises errors.

to zero.
Calling it on a value not stored with :raw will initialize that value
operator and can only be used on values written with the :raw option.
Increment a cached value. This method uses the Redis incr atomic

Cache Store API implementation. 
def increment(name, amount = 1, options = nil)
  instrument :increment, name, amount: amount do
    failsafe :increment do
      options = merged_options(options)
      key = normalize_key(name, options)
      redis.with do |c|
        c.incrby(key, amount).tap do
          write_key_expiry(c, key, options)
        end
      end
    end
  end
end