Thursday, August 9, 2018

SAP HANA Extended Application Services (SAP HANA XS) flavors

HANA has built-in an application server for native development in the SAP HANA environment. There are actually two flavors application servers. I depict here the two and mention some differences. 

HANA native application development resides on the XS server (or also called as XS Engine or just XS). The XS is a small footprint application server including: web server and basis for an application development environment.  The XS is installed on the same hardware as SAP HANA. It does extend the SAP HANA database. It makes a platform out of it.

XSC - SAP HANA XS classic, lightweight application server includes web based HTTP and OData services. It can consume HANA database artifacts (e.g. calculation views) and it has built in support for the SAP Fiori UI. Also supports transactional services based on core data services (CDS). It uses database permissions, there are DB users in HANA itself. It was introduced in SAP HANA SPS 05 (around year 2012). 

Programming model: OData REST services is generated from any existing SAP HANA Table or View. All metadata and source codes (XS server-side JavaScript (XSJS)) for XS Classic app are stored in the SAP HANA repository.

XSA - SAP HANA XS Advanced is a new application server for native development in the SAP HANA environment. It supersedes SAP HANA XS. It is decoupled from HANA, are not necessary users in HANA DB. XSA started to be delivered SAP HANA SPS 11 (around year 2015).

Programming model: UI rendering and other front end processing is normally done in web browser using HTML5 and client-side JavaScript. Application logic, business logic, calculations, and data processing talks place in HANA DB by using SQL, SQLScript procedures, Calculation Engine (CE) functions. Means data processing is performed in database - close to the data. Three runtimes currently supported: 

XSJS - same as in XSC
Node.js – to support asynchronous web programming model, to leverage node.js’s ecosystem as there are many open source nodejs modules
Java – as there is a huge number of popular Java frameworks out there

More information:
SAP HANA SPS 11 new developer features xs advanced

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