A request dispatcher can automatically switch between processing request dispatches (e.g., include( )) in a synchronous mode and an asynchronous mode. Each dispatch can be associated with a unique identification value such as a process ID or Uniform Resource Identifier (URI), historic metrics, and a ruleset. With each execution of the request dispatch, historic metrics can be collected. Metrics can include, but is not limited to, execution duration and/or execution frequency, processor load, memory usage, network input/output, number of dependent dispatches, and the like. Utilizing historic metrics, rules can be constructed for determining which mode to execute the subsequent execution of the dispatch. As such, runtime optimization of Web applications can be further improved.