+
+@section s4u_ex_actions Following Workload Traces
+
+This section details how to run trace-driven simulations. It is very
+handy when you want to test an algorithm or protocol that only react
+to external events. For example, many P2P protocols react to user
+requests, but do nothing if there is no such event.
+
+In such situations, you should write your protocol in C++, and separate
+the workload that you want to play onto your protocol in a separate
+text file. Declare a function handling each type of the events in your
+trace, register them using @ref xbt_replay_action_register in your
+main, and then run the simulation.
+
+Then, you can either have one trace file containing all your events,
+or a file per simulated process: the former may be easier to work
+with, but the second is more efficient on very large traces. Check
+also the tesh files in the example directories for details.
+
+ - <b>Communication replay</b>.
+ @ref examples/s4u/actions-comm/s4u_actions-comm.cpp \n
+ Presents a set of event handlers reproducing classical communication
+ primitives (asynchronous send/receive at the moment).
+
+ - <b>I/O replay</b>.
+ @ref examples/s4u/actions-storage/s4u_actions-storage.cpp \n
+ Presents a set of event handlers reproducing classical I/O
+ primitives (open, read, close).
+