Pre Cloud at eBay we managed 30k windows servers via a tool called site controller that referenced ALL servers as objects with properties of configuration state

Pre Cloud at eBay we managed 30k windows servers via a tool called site controller that referenced ALL servers as objects with properties of configuration state, build version and operational state. ALL databases had their startup configuration parameters defined per instance across datacenters. Furthermore SRE had tools to rate limit connections or restart of a database so that it was not overwhelmed by incoming connection requests. We also built tools to do fine grained definition of load balancers and what services were behind them to be able to redirect traffic on the fly and then reset to the original mappings once connectivity of the LBs was resolved. These tools weee centralized and available to both SRE and senior system administrators. These things evolved to new tools which accommodated a private cloud, then docker then Kubernetes. I left prior to kubernetes implementation.