Hi all,
I want to share with everyone how one of the amazing features provided by SAP BTP Kyma runtime helps you to build yours side-by-side applications.
What is a Service Mesh? ( source Official documentation ):
Modern applications are typically architected as distributed collections of microservices, with each collection of microservices performing some discrete business function. A service mesh is a dedicated infrastructure layer that you can add to your applications. It allows you to transparently add capabilities like observability, traffic management, and security, without adding them to your own code. The term “service mesh” describes both the type of software you use to implement this pattern, and the security or network domain that is created when you use that software.
As the deployment of distributed services, such as in a Kubernetes-based system, grows in size and complexity, it can become harder to understand and manage. Its requirements can include discovery, load balancing, failure recovery, metrics, and monitoring. A service mesh also often addresses more complex operational requirements, like A/B testing, canary deployments, rate limiting, access control, encryption, and end-to-end authentication.
Service-to-service communication is what makes a distributed application possible. Routing this communication, both within and across application clusters, becomes increasingly complex as the number of services grow. Istio helps reduce this complexity while easing the strain on development teams.
Too much documentation, let’s see it in action:
Architecture ( demo app used )
SAP BTP – KYMA – DATA CENTER
We can see how the Kyma cluster is on AWS data center
SAP BTP – KYMA – HOSTS
We can see the unique node inside of the cluster
SAP BTP – KYMA – PROCESSES
We can see all the processes running inside of the Kyma node like the SAP BTP Operator
SAP BTP – KYMA – SERVICES – SAP APP ROUTER
Finally the SAP APP Router running standalone on Kyma
SAP BTP – KYMA – SERVICES – SAP CAP APP
The SAP CAP APP running on Kyma
SAP BTP – KYMA – SERVICES – “ON-PREM” SYSTEM
The “ON-PREM” system running on localhost, connected to Kyma via Connectivity service and SAP Cloud Connector
SAP BTP – KYMA – SERVICES – INTERNET
The “Internet”, used to call the SAP BTP services like destination, html5 repository
SAP BTP – KYMA – SAP APP ROUTER to INTERNET
We can see how the SAP APP Router calls internet to fetch the static html files
SAP BTP – KYMA – SAP APP ROUTER to SAP CAP APP
Put all your attention to this, you can see the direct communication between the SAP APP Router to the SAP CAP APP running on Kyma ( the service mesh 
)
SAP BTP – KYMA – SAP CAP APP to INTERNET
We can see how the SAP CAP APP is going to internet to extract the JWT keys to validate the JWT tokens
SAP BTP – KYMA – SAP CAP APP to “ON-PREM”
We can see how the SAP CAP APP is going to internet to fetch all the destinations details to finally use the connectivity service to reach the “ON-PREM” system via SAP Cloud Connector.
I hope that you enjoyed it.
Kind Regards.
Max.