Network Deployment (Distributed operating systems), v8.0 > Reference > Administrator best practices
Dynamic caching with Asynchronous Request Dispatcher
Asynchronous Request Dispatcher (ARD) improves servlet response time when slow operations are logically separated and performed concurrently with other operations that are required to complete the response.
Servlet caching works with ARD include requests, with certain caveats. The dynamic caching service does not support the ESI and ExternalCache features when ARD is enabled, due to complex and intractable buffering issues with third party content.
If the include request has been cached by the dynamic cache service, the include request returns immediately with the response data written to the top-level response data for the servlet.
In combination with the Remote Request Dispatcher (RRD), include request processing can also be offloaded to other members in the application server core group, thus reducing resource requirements on the original application server.