Igor's questions

I already have memcached installed in my servers and I've modified the default php.ini to:

session.save_handler = memcached
session.save_path = "127.0.0.1:11211"

I'm using Amazon EC2 instances (Ubuntu 16.04 LTS) with Auto Scaling and Load Balancer, but I've a big question in my mind about the PHP memcached. First, explaining my problem: I've stored sessions in my Server A and I've another Server B also running. But, when I stop Server A (that I'm connected with sessions), the Load Balancer redirects me to Server B and it looks like the sessions are lost, because I'm disconnected of my website and he asks me to sign in again.

And I read this excerpt for use memcached for session storage on multiple servers (from here):

In your php.ini you should set session.save_path to the list of memcached servers, for example server1:11211, server2:11211.

But how can I say in who will be server1:11211 and server2:11211 being that I am using Auto Scaling and I may have "n" servers?

I own an EC2 instance running PHP and Node.js (socket.io), and to allow access, I freed ports 80 (Apache) and 8000 (Node) and everything worked fine (If I access www.mydomain.com the website is normally displayed, and if I access www.mydomain.com:8000/socket.io/socket.io.js the socket.io script is displayed). However, I want to set up an Elastic Load Balancer for this instance (Just for testing, because later I'll use it with Auto Scaling), so I created the Target Group with the following settings:

After that, I registered the instance in Target Group, and the status check worked perfectly:

So, in my Load Balancer (Application Load Balancer and not Classic Load Balancer) I added the following listeners (if I delete the 8000 listener, when I access DNS:8000 or DNS:8000/socket.io/socket.io.js nothing is shown, only the error ERR_CONNECTION_REFUSED):

And in the Security Group of this Load Balancer I also added ports 80 and 8000:

So when accessing the DNS name of Load Balancer it normally shows the website, however, if I try to access the DNS:8000/socket.io/socket.io.js it rewrites the URL to DNS:8000 and continues to show the website, and not the socket.io script. I already tried to add the Path Pattern /socket.io/* to the 8000 listener but it continues the same way. So, how can I do to be able to show the socket.io script?

I've the following code in my .htaccess file:

RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

The code above is for adding www to the domain if it does not have the www. But I have a domain like: myloadbalancername-432566808.us-west-1.elb.amazonaws.com (DNS from AWS Elastic Load Balancer) and this domain does not work with www. So, how can I add www for all domain requests, except for the specific domain?

RewriteCond %{REQUEST_URI} !myloadbalancername
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

I tried with the code above, to check if the domain name does not have the word, and then check if the domain does not have the www, but without success. I'm beginner with .htaccess so I don't know what I'm doing wrong.