SAS Viya's key features for installers.

- Architecture changed from monolithic to microservices
Comparing SAS 9, SAS Viya is completely different in terms of architecture. SAS decomposed metadata service.
SAS 9's architecture is monolithic and SAS Viya using microservice architecture. In 9, SAS components are tightly coupled, like Meta, compute and web tier.

In Viya, each functionality has its own component and most of them runs independtly as micro service.
For example: In SAS 9, we use SMC for user administration. So ultimately metadata service is responsible for serving this functionality.
In Viya, we have dedicated micro service called identity for this. Instead of SMC, we use Environment manager web portal for configuring identity functionality in SAS Viya.

Because of this microservice architecture, SAS users can achive:
- Because of independent microservice, applying hotfixe/upgrade becomes easier
- in case of changes in configuration, you just have to restart the respective micro service, instead of complete downtime.

- Less over head for Installers
SAS Viya uses ansible open source software for deployment. So in case of multi tier deployment, you don't have to run SAS Deployment wizard on every server.
You run the deployment from CAS Controller box. Since we configure passwordless communication between remote SAS Servers and CAS controller, ansible communicates remote servers and installs desired software packages.

- Upgrade/hotfix can be done quickly
SAS Viya installation packages are rpm based. So its easy to Upgrade or apply hotfixes using "rpm -Uvh" command. You don't have to stop entire environment, you just have stop respective sas micro service, upgrade rpm package and then start the micro service.