Lost session

[eluser]Unknown[/eluser]
Hi,
this topic is kinda old, but its my only google hit. I guest this issue is still bothering some people, so I've decided to write my story:

- // CI Version

Code:

define('CI_VERSION',    '1.7.0');

- from my config.php file:

Code:

$config['sess_cookie_name']    = 'some_name';
$config['sess_expiration']    = 28800;//8h
$config['sess_encrypt_cookie']    = TRUE;
$config['sess_use_database']    = TRUE;
$config['sess_table_name']    = 'ci_sessions';
$config['sess_match_ip']    = FALSE;
$config['sess_match_useragent']    = TRUE;
$config['sess_time_to_update']     = 300;

$config['cookie_domain']    = ".domain.com";
$config['cookie_prefix']    = "";
$config['cookie_path']    = "/";

- from time to time (its session time and current url/action independent) session is being lost
- my LOG is on

Code:

$config['log_threshold'] = 1;

- and I can see lots of this:

unserialize() [<a href='function.unserialize'>function.unserialize</a>]: Error at offset 176 of 176 bytes /xxx/xxx/xxx/system/libraries/Session.php 708

- after searching php.net I've found this comment:

for those who has error like "
error at offset .."

but doesn't know why.

This function might be usefull

Code:

$sObject3 = 'a:2:{i:0;s:1:"1";i:1;s:3654:"1a1dc91c907325c69271ddf0c944bc72";}';

print_r( __unserialize($sObject3  ));

function __unserialize($sObject) {
  
    $__ret =preg_replace('!s:(\d+):"(.*?)";!e', "'s:'.strlen('$2').':\"$2\";'", $sObject );
  
    return unserialize($__ret);
  
}

- so currently my guess is that session problems came from keeping some unsupported (by unserialize) data in user session
- I store lots of various information in my session data, but due to above discovery I've decided to keep it as small as possible - only user id
- so far I can say: looks like problem is mostly gone, but not in 100%

Hope this will help.
Cheers

ps. after searching bug reports I've found this:
http://codeigniter.com/bug_tracker/bug/6600/
Looks like this is another possible reason for session losing issue.