I'm running a web service that serves a mobile app on IIS 8 and SQL Server 2014, my service has a massive load and i'm trying to improve performance, most of the load is happening on SQL.

i don't think i have a bottleneck, my processor and ram is up to the max and i think my code is not that bad, am already using memcached and other stuff to avoid hitting SQL too much.

i know i can always upgrade the server hardware but i already have a spare server that i would like to use, so i was thinking to split the SQL load on the 2 servers.

What i was thinking of is to setup replication on the other server and do some load balancing, but am not sure how to do the load balance.

I know i can adjust my code to hit the other server for some queries but i was hoping to find a solution that avoid changing my code.

So my question is, What are the ways of doing load balancing between 2 SQL servers ?

I would appreciate suggestions or best practices or some directions.

Thanks.