Unexpected behavior with custom session handler in PHP 8.1 leading to session data not persisting
I'm encountering an issue with a custom session handler in PHP 8.1 where session data does not seem to persist between requests. I’ve implemented the `SessionHandlerInterface` to handle session management using a Redis backend. The `open`, `read`, `write`, and `close` methods are implemented, but for some reason, the session data is not being retained after the first request. Here's a simplified version of my session handler implementation: ```php class RedisSessionHandler implements SessionHandlerInterface { private $redis; public function open($savePath, $sessionName) { $this->redis = new Redis(); $this->redis->connect('127.0.0.1', 6379); return true; } public function read($sessionId) { return $this->redis->get($sessionId) ?: ''; } public function write($sessionId, $data) { return $this->redis->set($sessionId, $data); } public function close() { return $this->redis->close(); } // Other methods (destroy, gc) are implemented as well... } ``` I register the session handler using: ```php $handler = new RedisSessionHandler(); session_set_save_handler($handler, true); session_start(); ``` After starting a session and setting a value like this: ```php $_SESSION['user_id'] = 123; ``` When I try to access the `$_SESSION['user_id']` on a subsequent request, it shows as `null`. I also checked Redis and the session key appears to be stored correctly, but it seems like `session_write_close()` is not called correctly which might be causing it not to persist. In addition, I've confirmed that session IDs are not changing between requests (I printed them out in the logs), and I've ensured that garbage collection settings are not prematurely deleting the sessions. My server's session configuration in `php.ini` looks standard, with `session.gc_maxlifetime` set to 1440 seconds. Is there a common oversight I might be missing when using a custom session handler, or is there a specific configuration that needs to be set for PHP 8.1 sessions to work correctly with Redis?