Question

I’m developing on GAE using Resin, it seems that my PHP session on the production site is short lived and doesn’t get updated (i.e., making requests doesn’t seem to increase it’s expiry period). Local is fine, as long as I don’t close the tab, the session persists.

Any pointer on this? My users are getting frustrated as they are kicked very frequently 🙁

Answer 1

I think the code is the best tutorial 🙂

// global mem cache service handle
$MEM_CACHE_SERVICE = NULL;
// table to store session like information
$MY_SESSION_TABLE = array();

function load_mcache($key) {
    global $MEM_CACHE_SERVICE;
    if (!$MEM_CACHE_SERVICE) {
        import com.google.appengine.api.memcache.MemcacheServiceFactory;
        import com.google.appengine.api.memcache.Expiration;
        $MEM_CACHE_SERVICE = MemcacheServiceFactory::getMemcacheService();
    }
    return $MEM_CACHE_SERVICE->get($key);
}

function save_mcache($key, $value, $cache_time) {
    global $MEM_CACHE_SERVICE;
    if (!$MEM_CACHE_SERVICE) {
        import com.google.appengine.api.memcache.MemcacheServiceFactory;
        import com.google.appengine.api.memcache.Expiration;
        $MEM_CACHE_SERVICE = MemcacheServiceFactory::getMemcacheService();
    }
    $expiration = Expiration::byDeltaSeconds($cache_time);
    return $MEM_CACHE_SERVICE->put($key, $value, $expiration);
}

// unserializing array from mem cache
// if nothing found like first time and after a minute, then add key to the table
if (!($MY_SESSION_TABLE = unserialize(load_mcache($_REQUEST['JSESSIONID'])))) {
    // save something to cache on first page load because we didnt have anything
    $MY_SESSION_TABLE['key1'] = date('m/d/Y H:i:s');
    // using jsessionid as a mem cache key, serializing array and setting cache time to one minute
    save_mcache($_REQUEST['JSESSIONID'], serialize($MY_SESSION_TABLE), 60);
}

// now my session table is available for a minute until its initialized again
print_r($MY_SESSION_TABLE);

Now for proper session functionality you need to add set and get methods or even better a small class for handling it. Little abstraction to the classes and you could choose what kind of session mechanism to use with same library on different web app scenarios.