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Your LimeSurvey version: 6.x
Own server or LimeSurvey hosting:
Survey theme/template:
==================Hello everyone,We’re currently running LimeSurvey in a Kubernetes environment with multiple pods (horizontal scaling). Everything works fine when only one pod is active, but when multiple pods are running simultaneously, users are frequently logged out or encounter session-related errors such as “Invalid session key” or “Session expired”.It seems that LimeSurvey’s default file-based PHP session handling causes each pod to have its own isolated session storage, so users switching between pods lose their session.We need to run multiple pods to handle load testing and high-traffic scenarios, so disabling multi-pod setup isn’t an option for us.Could you please advise on the best practice or configuration for handling sessions in a multi-pod setup?
Specifically:

• Is it possible to configure LimeSurvey to use Redis or Memcached for session storage?
• Are there any recommended parameters or examples for
  Code:

  config.php

  or
  Code:

  security.php

  to make session handling cluster-safe?
• Alternatively, is enabling sticky sessions at the ingress/load balancer level an acceptable workaround?

Any guidance, documentation links, or examples from similar setups would be greatly appreciated.Thank you in advance!

Hi,

1. You can use DB session, it's done for this ( www.limesurvey.org/manual/Optional_settings/en#Session_settings ) and config.php comment part
2. You can configure your PHP to use www.php.net/manual/en/memcached.sessions.php or Redis cache. LimeSurvey use it transparently.


> Alternatively, is enabling sticky sessions at the ingress/load balancer level an acceptable workaround

Yes, there are some user using such solution.