在负载均衡设置中处理$ _SESSION对象，PHP

Question

I have a setup where I have a host which routes multiple requests in a load-balanced fashion. My backend uses PHP. Now, I need to use the $_SESSION object for some of my processing.

Will $_SESSION work where I have 3 backend servers which can receive any request at any time?

If not, Can one suggest alternatives to handle such cases?

EDIT: I do understand that we can store sessions in a database and find a way to track it. But, the problem in a realtime load-balanced production scenario is the number of calls that go into a DB. That can be a real bummer for my performance. I'm kind of hoping that, we can handle this at an webserver level.

Not sure, if it is possible, but, if two webservers have some kind of replication mechanism like databases do, it will be brilliant. I dont have to do a thing.

If such a thing does not exist, PHP should be modified to support it. That will actually, make it a seriously robust language.

Answer 1

Look into either memcache (Is it recommended to store PHP Sessions in MemCache?) or REDIS (https://joshtronic.com/2013/06/20/redis-as-a-php-session-handler/).

There is a good tutorial on setting up memcache on Ubuntu at https://www.globo.tech/learning-center/php-memcached-instances-ubuntu-16/. Which also covers using haproxy as a load balancer (although you may already a solution).

Perhaps have a read of https://blog.newtonhq.com/session-handling-for-1-million-requests-per-hour-68cdece15030.