How many HANA XS Server processes in scale-out?

[Former Member]

I am wondering does each node on a HANA Scale-out instance has its own XSEngine server processes or there is only 1 per system? If there is only 1 XSEngine process for the entire system, how do we prevent it from becoming bottleneck for the HANA XS based apps?

[Former Member · Accepted solution]

Hi Mangesh,

Which version of HANA are you currently using?

As of SPS 08: there is only 1 xsengine on a HANA Scale out instance on the MASTER node by default

From SPS09 and above versions; xsengine is by default embedded into the Indexserver, but you can add a separate xsengine service and this will stop the embedded service to be stopped and disabled.

I am not involved with too many applications that use the xsengine so I cannot guide you much on how to handle the bottleneck for xsengine based apps

Sunil

[thomas_jung · Accepted solution]

The information in this thread is not correct.

In a scale out system you do get an XSEngine process on each node. The central web dispatcher uses a round robin load distribution approach to spread requests across each node.

Although I don't see where embedded mode is relevant here, that information stated previously also isn't correct. Embedded mode has been an option since SPS 05. However the default state remains non-embedded even on SPS 09 and beyond.  The one exception is in MDC, each tenant DB instance has its own XSEngine process which does run embedded in an effort to keep the tenant footprint a little smaller.

As far as keeping XS from becoming a bottleneck: use it as intended. It's a lightweight pass thru layer. Keep your data intensive processing and flow within the DB by putting it in Views and Stored Procedures. Never return a result set to XS which is largwe than what you intend to send to the client side. Do all your filtering and paging within the data base.  Remember that XS is always stateless.

[Former Member · Accepted solution]

Thank you, Thomas. Are there any published / unpublished benchmarks available that shows the performance of REST based web services (XSJS, not OData) exposed via XS engine? We are planning to use the Scale-out HANA instance for exposing a few of such web services, but we are expecting over 3000 calls per minute. Which is why we were hoping that individual XS engine on each scale out node would make more sense to spread the workload.

Any advice on this scenario?

[Former Member · Accepted solution]

Thank you Thomas for the corrections on the 2 points above

We have a 3+1(standby) node HANA(SPS08) Scale out system for BW) and do not have 1 XSEngine per node. There is just 1 XSEngine on the Master node. I am sure we have not made any changes on the system post installation so that led me to the answer above. So in such a case how does HANA process the requests for the XSEngine? Is it non embedded on MASTER and embedded on SLAVE nodes? Are there any scripts to identify embedded and non embedded XSEngine?

Regarding the embedded XSEngine I should have mentioned my comments were for a MDC setup on SPS09 and not for a single container system

Sunil

[thomas_jung · Accepted solution]

What you should do is make sure that your system is tuned appropriately for the query execution load.  If designed correctly 90%+ processing should be happening at the DB level and not the XS level. If you do this the standard SAP sizing already has the necessary overhead built in for normal usage of XS.

[thomas_jung · Accepted solution]

I can't speak to your specific system.  Perhaps some post configuration steps were missed.  Really though if your system is used for BW you don't need XS as BW uses the ABAP AS and not XS at all.  Perhaps that is why your system is configured the way it is.

As far as running in embedded mode, look in the xsengine.ini configuration you will see if your system is configured to run embedded.

[Former Member · Accepted solution]

Thank you.

[Former Member]

Hi Thomas

I have come across the requirement to convert SAP - BSP Application into UI5.

Our client using BSP application from last 5 years, and those application build through HTML+CSS+AJAX and JAVA Script.

My question is: Is it possible BSP application can convert into UI5?

                       Can we change the look and feel of BSP using UI5 libraries ?

                       We run BSP converted UI5 application in Eclipse?

Kindly suggest me ASAP...

Thanks in Advance.

Akshath.L.T

[SRudra]

Hi Akshath,

Quick pointers:

a) Check the current set of SAPUI5 libraries that your server support

b) Change your application UI controls/elements (ActionSheet, Buttons, etc) to support the library your server supports. So all BSP related controls/elements to be replaced by UI5 related controls/elements.

As you will be required to support the updated UI5 libraries for your application, it would be better, if you could also include changes to enhance to mobility support to the application. All mobile related API start as sap.m.xxx

BTW, you should start a separate discussion on your requirements, rather than hijacking this thread.

Regards,

Sukanta Rudra