Users take sessions of other users when sessions are stored in memcached (Rails)

Question

I have a very weird problem, when storing my session in Memcached. From time to time some users takes the session of others. E.g. John, becomes logged in as Maria, Maria as

Answer 1

I never ran into such a problem before, I just can't imagine that it's even happening. This is my conf:

require 'memcache'

memcache_options = {
  :c_threshold => 10_000,
  :compression => true,
  :debug => false,
  :namespace => "app-me",
  :readonly => false,
  :urlencode => false
}
memcache_servers = [ "#{MEMCACHED_HOST}:#{MEMCACHED_PORT}" ]

CACHE = MemCache.new memcache_options

CACHE.servers = memcache_servers
ActionController::Base.session_options[:expires] = 1800
ActionController::Base.session_options[:cache] = CACHE

# Inside the Rails initializer
config.action_controller.session_store = :mem_cache_store