Key ingredients to achieve effective 1/O The complexity of asynchronous I/O Some consequences o involves multi-threaded multi-process approach o with a background task for the actual transfer. o involves out of order transfers o no garantee on the order in which transfers will arrive to destination especially in case of failures o involves queue management on the caller side to not send too much in parallel to adapt to network efficiency Libraries Do not try to do all that by hand Use a library that does(most of)it for you latancy asyne mig 11/57 S.Ponce-CERNKey ingredients to achieve effective I/O 11 / 57 S. Ponce - CERN async IOopt struct caching c/c latency async msgQ The complexity of asynchronous I/O Some consequences involves multi-threaded / multi-process approach with a background task for the actual transfer. involves out of order transfers no garantee on the order in which transfers will arrive to destination especially in case of failures involves queue management on the caller side to not send too much in parallel to adapt to network efficiency Libraries Do not try to do all that by hand Use a library that does (most of) it for you