Using memcached to store session data, is it safe?

I should develop web site to complete some data about books with great auto complete. Each page has around 1500 ajax request to server!

So I decided to do main part of it with Yii framework and instead of using ajax,us Socket.IO of NodeJS for faster response.

Now the problem is sync session data between two programming language. Is it safe to use memcached to store it?

I mean save SESSIONID as key name in memcached and using JSON for value. so I can access it by PHP and NodeJS. Is it safe?

I wouldn't suggest using Memcached. The cache can invalidate at any time and you'll end up loosing data. I would recommend you use a solution such as Redis.

I would not recommend using Memcached for this - once your cache becomes full it will start deleting data and / or if your Memcached server crashes then you will also lose the data.

I would recommend using something like Redis or Membase.