Configuring Portal in the ArcGIS Enterprise failover mode will affect the ArcGIS server in HA mode .in this scenario the portal is active node and the second joind machine is passive. I configured the NLB to send 100 % request to the first portal then the portal will communicate with one of the ArcGIS server what if the active node faild while it is passing the request from the ArcGIS server will the passive node swich on and still hold the requested result.
this is still under testing from my side any advice., is this supported .JQuinn-esristaff
I'm not sure why you would want to only send requests to one node in your configuration, especially in a multi-machine site for Server. Multi-machine sites will give you give you both redundancy as well as additional processing power. Sending requests only to one Server only gives you redundancy.
Anyway, it sounds like your question is if a request is coming in to the primary/active server and the server goes down, does the request make it to the standby server. No, it shouldn't. If the request is still processing on the primary machine, the LB is just going to wait for a response from that machine, (200 if it succeeded or 5XX if it didn't, for example). There's no mechanism to send it to the standby.