Hi @KIRUBAKARAN J A ,
What you're looking for is called a Scale Out Deployment.
Scale-out deployments consist of:
1.Two or more report server instances sharing a single report server database.
2.Optionally, a network load-balanced (NLB) cluster to spread interactive user load across the report server instances.
Here is the official documentation for your reference.
The youtube video is also a good tutorial to refer.
Other related article:https://www.sqlshack.com/scaling-out-reporting-services-changes-in-sql-server-2016/
Please also notice that only Enterprise and Developer SSRS2016 support Scale-out deployment said here.
Before you configure Scale-out deployment, make sure that you have back up the database and encryption key.
Both the two different web service URL & web Portal URL could access the same report server.
If server1 down then we could use server2 web url to access the report server.
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