Are there any performance benefits to using an API key?

Products

• Rally On-Premise
• Rally SaaS

Issue/Introduction

Are there any performance benefits to using an API key instead of basic authentication when making WSAPI requests?

Environment

Release:
Component: ACSAAS

Resolution

Yes, maintaining ZSESSIONID and JSESSIONID allows us to do some authentication caching and avoid calling our authentication services. Using basic authentication means an extra server call on the backend.
Additionally, maintaining the JSESSIONID cookie "pins" you to a specific app server, increasing the amount of data that is already in cache for the request.