SimGrid  3.18
Versatile Simulation of Distributed Systems
examples/s4u/energy-boot/s4u-energy-boot.cpp
/* Copyright (c) 2007-2017. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
/* This is an example of how the bootup and shutdown periods can be modeled
* with SimGrid, taking both the time and overall consumption into account.
*
* The main idea is to augment the platform description to declare fake
* pstate that represent these states. The CPU speed of these state is zero
* (the CPU delivers 0 flop per second when booting) while the energy
* consumption is the one measured on average on the modeled machine.
*
* When you want to bootup the machine, you set it into the pstate encoding
* the boot (3 in this example), and leave it so for the right time using a
* sleep_for(). During that time no other execution can progress since the
* resource speed is set at 0 flop/s in this fake pstate. Once this is over,
* the boot is done and we switch back to the regular pstate. Conversely,
* the fake pstate 4 is used to encode the shutdown delay.
*
* Some people don't like the idea to add fake pstates for the boot time, and
* would like SimGrid to provide a "cleaner" model for that. But the "right"
* model depends on the study you want to conduct. If you want to study the
* instantaneous consumption of a rebooting data center, the model used here
* is not enough since it considers only the average consumption over the boot,
* while the instantaneous consumption changes dramatically. Conversely, a
* model taking the instantaneous changes into account will be very difficult
* to instantiate correctly (which values will you use?), so it's not adapted
* to most studies. At least, fake pstates allow you to do exactly what you
* need for your very study.
*/
#include "simgrid/s4u.hpp"
XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_test, "Messages specific for this example");
static void simulate_bootup(simgrid::s4u::Host* host)
{
int previous_pstate = host->getPstate();
XBT_INFO("Switch to virtual pstate 3, that encodes the 'booting up' state in that platform");
host->setPstate(3);
XBT_INFO("Actually start the host");
host->turnOn();
XBT_INFO("Wait 150s to simulate the boot time.");
XBT_INFO("The host is now up and running. Switch back to previous pstate %d", previous_pstate);
host->setPstate(previous_pstate);
}
static void simulate_shutdown(simgrid::s4u::Host* host)
{
int previous_pstate = host->getPstate();
XBT_INFO("Switch to virtual pstate 4, that encodes the 'shutting down' state in that platform");
host->setPstate(4);
XBT_INFO("Wait 7 seconds to simulate the shutdown time.");
XBT_INFO("Switch back to previous pstate %d, that will be used on reboot.", previous_pstate);
host->setPstate(previous_pstate);
XBT_INFO("Actually shutdown the host");
host->turnOff();
}
static int monitor()
{
XBT_INFO("Initial pstate: %d; Energy dissipated so far:%.0E J", host1->getPstate(),
XBT_INFO("Sleep for 10 seconds");
XBT_INFO("Done sleeping. Current pstate: %d; Energy dissipated so far: %.2f J", host1->getPstate(),
simulate_shutdown(host1);
XBT_INFO("Host1 is now OFF. Current pstate: %d; Energy dissipated so far: %.2f J", host1->getPstate(),
XBT_INFO("Sleep for 10 seconds");
XBT_INFO("Done sleeping. Current pstate: %d; Energy dissipated so far: %.2f J", host1->getPstate(),
simulate_bootup(host1);
XBT_INFO("Host1 is now ON again. Current pstate: %d; Energy dissipated so far: %.2f J", host1->getPstate(),
return 0;
}
int main(int argc, char* argv[])
{
simgrid::s4u::Engine e(&argc, argv);
xbt_assert(argc == 2, "Usage: %s platform_file\n\tExample: %s platform.xml\n", argv[0], argv[0]);
e.loadPlatform(argv[1]);
simgrid::s4u::Actor::createActor("Boot Monitor", simgrid::s4u::Host::by_name("MyHost2"), monitor);
e.run();
XBT_INFO("End of simulation.");
return 0;
}