The below are the architecture components ( processes/ services ) in HANA Database

  1. Name Server
  2. Index server
  3. Statistics Service/server
  4. Pre-processor
  5. Compile server
  6. Daemon
  7. Web dispatcher
  8. Start service and
  9. XS engine ( Optional )

Name server : Will hold the information on HANA DB landscape ( Details of other nodes in the landscape ..etc )  and data distribution among the Landscape. any request will be routed through Master node ( from master Name server )

Index server :  The main HANA DB service which holds data and process the requests like data loads, quires, calculations..etc.Every request will be routed through master index server ( Receiving the request , split SQL for processing and collection of processed results and deliver the requested data to application ).

Statistics service/ Server : In latest HANA DB versions Statistics service is part of Index server ( Service ). In earlier releases it was a separate process and was part of the server where Master Index server is running. This Statistics server / service will hold all monitoring related information ( Status , Performance and resource consumption ). incase of any alerts all historical information also will be available.

Pre-Processor : This will keep all the unstructured data into HANA DB

Compile server:  This is to perform compilation of stored procedures and Programs

Daemon :  This will start all other processes and keep them running

Start Service : is responsible  to start / stop all other services.

XS Engine: This is like an app server and this is an optional service.

Please note that each of the above processes will persist data in their corresponding data volumes.