From Downtime to Uptime: Building Resilient PHP Apps - Part IV

Welcome back to our journey into resilient PHP applications. In Part III, we focused on traffic resilience with **HAProxy** and saw how a healthy edge keeps bad nodes out of rotation. That only helps if the user can land on any healthy node and keep working. If their session lives on the server that just died, the infrastructure may be healthy while the user still experiences an outage.