session redundancy weird behaviour when reopening session during request

[thesource93]

if session is commited, then reopened, changed and during that time key becomes missing on one of the servers in pool , session is not loaded. however after the final session_write the keys are available on both memcached instances.

eg code from tests/044.phpt

// Test lost session on server1
session_id($balanceKey1);
@session_start();
$_SESSION['key'] = 'Test2';
session_write_close();
unset($_SESSION['key']);

$result = $memcache1->delete($balanceKey1);
var_dump($result);

session_id($balanceKey1);
@session_start();
var_dump($_SESSION);
session_write_close();

// Test lost session on server2                                                                                                                                                                                    
session_id($balanceKey1);
@session_start();
$_SESSION['key'] = 'Test3';
session_write_close();
unset($_SESSION['key']);

$result = $memcache2->delete($balanceKey1);
var_dump($result);

session_id($balanceKey1);
@session_start();
var_dump($_SESSION);
session_write_close();