My PHP session won't save on hostgator

Question

Out of my head. How to fix this one. My session not working on hostgator server. But on other server it working fine.

Here an example the code.

<form action="/payment-select/" method="post">
 <select name="payment" onchange="this.form.submit()">
 <option value=""<?php if(empty($_SESSION['payment'])) { echo ' selected="selected"'; } ?>><?php echo $lang_please_select; ?></option>
 <?php 
  $sp = 'SELECT * FROM payment';
  $qp   = $db->rq($sp);
  while($payment = $db->fetch($qp)) {
  ?>
 <option value="<?php echo $payment['bank']; ?>"<?php if($_SESSION['payment'] == $payment['bank']) { echo ' selected="selected"'; } ?>><?php echo $payment['bank']; ?></option>
 <?php } ?>
 </select>
 </form>

The /payment-select/

include_once('includes/connection.php'); // session_start() here
include_once('includes/formatting.php');

$_SESSION['payment'] = strip_html_tags($_POST['payment']); 

header("location:/payment/");
exit();

Update

1. All required pages have session_start() on the top.
2. I install the script to server A working fine. Then server B fine.. But on hostgator with same phpinfo the $_SESSION['payment'] won't save after header redirect to /payment/ page.

I'm not share the session between server. It's something like I install wordpress on server A ok, Server B ok and Server C problem. ( the situation by example )

Answer 1

It would be helpful to clarify how this isn't working. My initial suggestion would be whether you have session_start(); included on all the pages where $_SESSION is utilised. Without knowing further what is not functioning it's hard to suggested anything further.

Answer 2

Sessions are not shared between different servers, so you'll have to work out some way to pass those variables along with the transactions - assuming they are on different machines.

Answer 3

Sessions are not shared between servers. If you are passing a user with a session on one server to a page on another (where you would like to persist the session) you will need to develop a method of handing that off. Preferably with a token and encrypted serialized $_SESSION which can then be authenticated and loaded.

Host 1

$s = serialize($_SESSION);
$enc = encrypt($s); // However you want to encrypt it, I recommend it.
$token = gen_token(); // Again, find a good way to generate a secure token;

Host 2

$token = $_POST['token'];
if(is_valid($token))
{
    // Load the session (wrapped in a function, basically loop through the
    // array and load the respective values.
    load_session(unserialize(decrypt($_POST['enc'])));
}