Sticky Sessions

Overview

Enabling sticky session in your TAS app creates a persisted session between the user and the original server the load balancer routed them to
Use this feature when user session state is stored on the application and requires the user to stay on the same app instance

DISCLAIMER

Use of sticky sessions is consider a cloud ANTI-PATTERN
Using sticky sessions will prevent the application from being dynamically scaled
Applications also cannot support zero downtime or blue/green deployments
Any change in application instances (whether it be scale up/down, restart, or restage) will disrupt user sessions
Consider using a pattern such as Redis Session Store instead for a cloud-native approach to session management

Enabling Sticky Sessions

By Default, TAS will automatically start sticky sessions if the application creates a cookie named JSESSIONID
Once this cookie is created, TAS will create an additional cookie named __VCAP_ID__
The VCAP ID is the ID of the application instance to send traffic to

Using ASP.NET Session

Change the ASP.NET Session cookie name to JSESSIONID

Edit `Web.config`

<sessionState cookieName="JSESSIONID" />

Changing the default cookie name

Adding more sticky session cookie names has to be configured in OpsMan by a operator of TAS
Every TAS installation has JSESSIONID as the default