3149646 - XSA startup failure due to error "Invalid routing mode"

hdbxscontroller service failed to startup.

In xscontroller.out, the following error messages are observed.

. FAILED!
 Initialization failed: com.sap.xs2rt.controller.ControllerExceptions$ControllerStartUpException: Invalid routing mode 'hostnames api_url ='
Stopped Command Server on port 30030.
Error during Controller shutdown: while trying to invoke the method com.sap.xs2rt.core.generated.rest.model.Info$DatabaseType.equals(java.lang.Object) of a null object returned from com.sap.xs2rt.controller.impl.ControllerImpl.getDatabaseType()
java.lang.NullPointerException: while trying to invoke the method com.sap.xs2rt.core.generated.rest.model.Info$DatabaseType.equals(java.lang.Object) of a null object returned from com.sap.xs2rt.controller.impl.ControllerImpl.getDatabaseType()
 at com.sap.xs2rt.controller.impl.ControllerImpl.tearDown(ControllerImpl.java:1969)
 at com.sap.xs2rt.controller.impl.ControllerImpl.startUp(ControllerImpl.java:749)
 at com.sap.xs2rt.controller.impl.ControllerConsole.main(ControllerConsole.java:533)
Failed to start controller
com.sap.xs2rt.controller.ControllerExceptions$ControllerStartUpException: Invalid routing mode 'hostnames api_url ='
 at com.sap.xs2rt.controller.impl.ControllerImpl.startUpHanaSettings(ControllerImpl.java:797)
 at com.sap.xs2rt.controller.impl.ControllerImpl.lambda$startUp$0(ControllerImpl.java:727)
 at com.sap.xs2rt.controller.impl.ControllerStartupManager.lambda$submit$0(ControllerStartupManager.java:153)
 at java.util.concurrent.FutureTask.run(FutureTask.java:266)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:836)
Caused by: java.lang.IllegalArgumentException: Unsupported routing mode 'hostnames api_url ='
 at com.sap.xs2rt.server.router.PlatformRouter$RoutingMode.fromString(PlatformRouter.java:50)
 at com.sap.xs2rt.controller.impl.ControllerImpl.startUpHanaSettings(ControllerImpl.java:795)
 ... 6 more
FAILED to start: Invalid routing mode 'hostnames api_url ='

Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• SAP HANA Platform Edition 2.0 or higher
• SAP HANA Extended Application Services

HANA, XSA, XS Advanced, FAILED to start, Invalid routing mode, xscontroller.ini, Invalid default_domain, Invalid api_url , KBA , BC-XS-RT , XS Advanced Runtime / XS Controller , Problem