Session Handling Errors in PHP 7 using DB driver

[anaxmedia]

Recently upgraded my M2 sample site to PHP 7 to do some performance benchmarking and I'm running into the following issue when trying to do anything session related (admin login, checkout, account functions, etc).

I use Redis backend for cache and Memcache for php session cache.

Getting the following error in Magento 2 on PHP 7.0.1:

session_regenerate_id(): Failed to create(read) session ID: user (path: aws-memcache-instance:11211) in /var/www/mysite.com/html/vendor/magento/framework/Session/SessionManager.php on line 473

Same issue with CM Redis and another M2 extension:

Inchoo/Inchoo_PHP7#4
colinmollenhour/Cm_RedisSession#70

It appears to be an issue with the read function not always returning a string.

As a temporary fix I cast the return value for the read() function in the SessionHandler as a string.

[johnbendi]

@anaxmedia Please can you show exactly how you did the casting?

[pmquan]

I got a similar issue with my setup CentOS 7 + PHP 7.02. I did exactly as anaxmedia's fix.
Changed file vendor/magento/framework/Session/SaveHandler.php line 112
From: return $this->saveHandlerAdapter->read($sessionId);
To: return (string)$this->saveHandlerAdapter->read($sessionId);

My system detailed information:
php-pecl-memcached-2.2.0
libmemcached-1.0.16
php-7.0.2
apache-itk

[shiftedreality]

Hi @anaxmedia

Please ,try to reproduce this bug in latest developer branch.
Looks like #2454 should fix your case

[ostark]

It looks like these patches tackle this session handler issue in PHP 7 core:
https://github.com/php/php-src/blob/PHP-7.0/NEWS#L46

[mazhalai]

@anaxmedia any update on this issue?

[mazhalai]

@anaxmedia closing due to responsiveness.