1 /* Copyright (c) 2013-2018. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "src/plugins/vm/VmLiveMigration.hpp"
7 #include "simgrid/Exception.hpp"
8 #include "src/instr/instr_private.hpp"
9 #include "src/plugins/vm/VirtualMachineImpl.hpp"
10 #include "src/plugins/vm/VmHostExt.hpp"
12 XBT_LOG_NEW_DEFAULT_CATEGORY(vm_live_migration, "S4U virtual machines live migration");
16 simgrid::xbt::Extension<s4u::Host, VmMigrationExt> VmMigrationExt::EXTENSION_ID;
18 void VmMigrationExt::ensureVmMigrationExtInstalled()
20 if (not EXTENSION_ID.valid())
21 EXTENSION_ID = simgrid::s4u::Host::extension_create<VmMigrationExt>();
24 void MigrationRx::operator()()
26 XBT_DEBUG("mig: rx_start");
27 bool received_finalize = false;
29 std::string finalize_task_name =
30 std::string("__mig_stage3:") + vm_->get_cname() + "(" + src_pm_->get_cname() + "-" + dst_pm_->get_cname() + ")";
32 while (not received_finalize) {
33 std::string* payload = static_cast<std::string*>(mbox->get());
35 if (finalize_task_name == *payload)
36 received_finalize = true;
41 // Here Stage 1, 2 and 3 have been performed.
42 // Hence complete the migration
44 /* Update the vm location */
45 /* precopy migration makes the VM temporally paused */
46 xbt_assert(vm_->get_state() == s4u::VirtualMachine::state::SUSPENDED);
48 /* Update the vm location and resume it */
52 // Now the VM is running on the new host (the migration is completed) (even if the SRC crash)
53 vm_->get_impl()->is_migrating_ = false;
54 XBT_DEBUG("VM(%s) moved from PM(%s) to PM(%s)", vm_->get_cname(), src_pm_->get_cname(), dst_pm_->get_cname());
56 if (TRACE_vm_is_enabled()) {
57 static long long int counter = 0;
58 std::string key = std::to_string(counter);
62 container_t msg = simgrid::instr::Container::by_name(vm_->get_name());
63 simgrid::instr::Container::get_root()->get_link("VM_LINK")->start_event(msg, "M", key);
65 // destroy existing container of this vm
66 simgrid::instr::Container::by_name(vm_->get_name())->remove_from_parent();
68 // create new container on the new_host location
69 new simgrid::instr::Container(vm_->get_cname(), "VM", simgrid::instr::Container::by_name(dst_pm_->get_name()));
72 msg = simgrid::instr::Container::by_name(vm_->get_name());
73 simgrid::instr::Container::get_root()->get_link("VM_LINK")->end_event(msg, "M", key);
75 // Inform the SRC that the migration has been correctly performed
76 std::string* payload = new std::string("__mig_stage4:");
77 *payload = *payload + vm_->get_cname() + "(" + src_pm_->get_cname() + "-" + dst_pm_->get_cname() + ")";
79 mbox_ctl->put(payload, 0);
81 XBT_DEBUG("mig: rx_done");
84 static sg_size_t get_updated_size(double computed, double dp_rate, sg_size_t dp_cap)
86 sg_size_t updated_size = static_cast<sg_size_t>(computed * dp_rate);
87 XBT_DEBUG("updated_size %llu dp_rate %f", updated_size, dp_rate);
88 if (updated_size > dp_cap) {
89 updated_size = dp_cap;
95 sg_size_t MigrationTx::sendMigrationData(sg_size_t size, int stage, int stage2_round, double mig_speed, double timeout)
97 sg_size_t sent = size;
98 std::string* msg = new std::string("__mig_stage");
99 *msg = *msg + std::to_string(stage) + ":" + vm_->get_cname() + "(" + src_pm_->get_cname() + "-" +
100 dst_pm_->get_cname() + ")";
102 double clock_sta = s4u::Engine::get_clock();
104 s4u::Activity* comm = nullptr;
107 comm = mbox->put_init(msg, size)->set_rate(mig_speed)->wait_for(timeout);
109 comm = mbox->put_async(msg, size)->wait_for(timeout);
110 } catch (xbt_ex& e) {
112 sg_size_t remaining = static_cast<sg_size_t>(comm->get_remaining());
113 XBT_VERB("timeout (%lf s) in sending_migration_data, remaining %llu bytes of %llu", timeout, remaining, size);
119 double clock_end = s4u::Engine::get_clock();
120 double duration = clock_end - clock_sta;
121 double actual_speed = size / duration;
124 XBT_DEBUG("mig-stage%d.%d: sent %llu duration %f actual_speed %f (target %f)", stage, stage2_round, size, duration,
125 actual_speed, mig_speed);
127 XBT_DEBUG("mig-stage%d: sent %llu duration %f actual_speed %f (target %f)", stage, size, duration, actual_speed,
133 void MigrationTx::operator()()
135 XBT_DEBUG("mig: tx_start");
137 double host_speed = vm_->get_pm()->get_speed();
138 const sg_size_t ramsize = vm_->get_ramsize();
139 const double dp_rate =
140 host_speed ? (sg_vm_get_migration_speed(vm_) * sg_vm_get_dirty_page_intensity(vm_)) / host_speed : 1;
141 const sg_size_t dp_cap = sg_vm_get_working_set_memory(vm_);
142 const double mig_speed = sg_vm_get_migration_speed(vm_);
143 double max_downtime = sg_vm_get_max_downtime(vm_);
145 double mig_timeout = 10000000.0;
146 bool skip_stage2 = false;
148 size_t remaining_size = ramsize;
149 size_t threshold = 0.0;
151 /* check parameters */
153 XBT_WARN("migrate a VM, but ramsize is zero");
155 if (max_downtime <= 0) {
156 XBT_WARN("use the default max_downtime value 30ms");
160 /* Stage1: send all memory pages to the destination. */
161 XBT_DEBUG("mig-stage1: remaining_size %zu", remaining_size);
162 sg_vm_start_dirty_page_tracking(vm_);
164 double computed_during_stage1 = 0;
165 double clock_prev_send = s4u::Engine::get_clock();
168 /* At stage 1, we do not need timeout. We have to send all the memory pages even though the duration of this
169 * transfer exceeds the timeout value. */
170 XBT_VERB("Stage 1: Gonna send %llu bytes", ramsize);
171 sg_size_t sent = sendMigrationData(ramsize, 1, 0, mig_speed, -1);
172 remaining_size -= sent;
173 computed_during_stage1 = sg_vm_lookup_computed_flops(vm_);
175 if (sent < ramsize) {
176 XBT_VERB("mig-stage1: timeout, force moving to stage 3");
178 } else if (sent > ramsize)
181 } catch (xbt_ex& e) {
182 // hostfailure (if you want to know whether this is the SRC or the DST check directly in send_migration_data code)
183 // Stop the dirty page tracking an return (there is no memory space to release)
184 sg_vm_stop_dirty_page_tracking(vm_);
188 double clock_post_send = s4u::Engine::get_clock();
189 mig_timeout -= (clock_post_send - clock_prev_send);
190 if (mig_timeout < 0) {
191 XBT_VERB("The duration of stage 1 exceeds the timeout value, skip stage 2");
195 /* estimate bandwidth */
196 double bandwidth = ramsize / (clock_post_send - clock_prev_send);
197 threshold = bandwidth * max_downtime;
198 XBT_DEBUG("actual bandwidth %f (MB/s), threshold %zu", bandwidth / 1024 / 1024, threshold);
200 /* Stage2: send update pages iteratively until the size of remaining states becomes smaller than threshold value. */
201 if (not skip_stage2) {
203 int stage2_round = 0;
205 sg_size_t updated_size = 0;
206 if (stage2_round == 0) {
207 /* just after stage1, nothing has been updated. But, we have to send the data updated during stage1 */
208 updated_size = get_updated_size(computed_during_stage1, dp_rate, dp_cap);
210 double computed = sg_vm_lookup_computed_flops(vm_);
211 updated_size = get_updated_size(computed, dp_rate, dp_cap);
214 XBT_DEBUG("mig-stage 2:%d updated_size %llu computed_during_stage1 %f dp_rate %f dp_cap %llu", stage2_round,
215 updated_size, computed_during_stage1, dp_rate, dp_cap);
217 /* Check whether the remaining size is below the threshold value. If so, move to stage 3. */
218 remaining_size += updated_size;
219 XBT_DEBUG("mig-stage2.%d: remaining_size %zu (%s threshold %zu)", stage2_round, remaining_size,
220 (remaining_size < threshold) ? "<" : ">", threshold);
221 if (remaining_size < threshold)
225 double clock_prev_send = s4u::Engine::get_clock();
227 XBT_DEBUG("Stage 2, gonna send %llu", updated_size);
228 sent = sendMigrationData(updated_size, 2, stage2_round, mig_speed, mig_timeout);
229 } catch (xbt_ex& e) {
230 // hostfailure (if you want to know whether this is the SRC or the DST check directly in send_migration_data
232 // Stop the dirty page tracking an return (there is no memory space to release)
233 sg_vm_stop_dirty_page_tracking(vm_);
236 double clock_post_send = s4u::Engine::get_clock();
238 if (sent == updated_size) {
239 /* timeout did not happen */
240 double bandwidth = updated_size / (clock_post_send - clock_prev_send);
241 threshold = bandwidth * max_downtime;
242 XBT_DEBUG("actual bandwidth %f, threshold %zu", bandwidth / 1024 / 1024, threshold);
243 remaining_size -= sent;
245 mig_timeout -= (clock_post_send - clock_prev_send);
246 xbt_assert(mig_timeout > 0);
248 } else if (sent < updated_size) {
249 /* When timeout happens, we move to stage 3. The size of memory pages
250 * updated before timeout must be added to the remaining size. */
251 XBT_VERB("mig-stage2.%d: timeout, force moving to stage 3. sent %llu / %llu, eta %lf", stage2_round, sent,
252 updated_size, (clock_post_send - clock_prev_send));
253 remaining_size -= sent;
255 double computed = sg_vm_lookup_computed_flops(vm_);
256 updated_size = get_updated_size(computed, dp_rate, dp_cap);
257 remaining_size += updated_size;
264 /* Stage3: stop the VM and copy the rest of states. */
265 XBT_DEBUG("mig-stage3: remaining_size %zu", remaining_size);
267 sg_vm_stop_dirty_page_tracking(vm_);
270 XBT_DEBUG("Stage 3: Gonna send %zu bytes", remaining_size);
271 sendMigrationData(remaining_size, 3, 0, mig_speed, -1);
272 } catch (xbt_ex& e) {
273 // hostfailure (if you want to know whether this is the SRC or the DST check directly in send_migration_data code)
274 // Stop the dirty page tracking an return (there is no memory space to release)
279 // At that point the Migration is considered valid for the SRC node but remind that the DST side should relocate
280 // effectively the VM on the DST node.
281 XBT_DEBUG("mig: tx_done");
286 static void onVirtualMachineShutdown(simgrid::s4u::VirtualMachine& vm)
288 if (vm.get_impl()->is_migrating_) {
289 vm.extension<simgrid::vm::VmMigrationExt>()->rx_->kill();
290 vm.extension<simgrid::vm::VmMigrationExt>()->tx_->kill();
291 vm.extension<simgrid::vm::VmMigrationExt>()->issuer_->kill();
292 vm.get_impl()->is_migrating_ = false;
296 void sg_vm_live_migration_plugin_init()
298 sg_vm_dirty_page_tracking_init();
299 simgrid::vm::VmMigrationExt::ensureVmMigrationExtInstalled();
300 simgrid::s4u::VirtualMachine::on_shutdown.connect(&onVirtualMachineShutdown);
303 simgrid::s4u::VirtualMachine* sg_vm_create_migratable(simgrid::s4u::Host* pm, const char* name, int coreAmount,
304 int ramsize, int mig_netspeed, int dp_intensity)
306 simgrid::vm::VmHostExt::ensureVmExtInstalled();
308 /* For the moment, intensity_rate is the percentage against the migration bandwidth */
310 sg_vm_t vm = new simgrid::s4u::VirtualMachine(name, pm, coreAmount, static_cast<sg_size_t>(ramsize) * 1024 * 1024);
311 sg_vm_set_dirty_page_intensity(vm, dp_intensity / 100.0);
312 sg_vm_set_working_set_memory(vm, vm->get_ramsize() * 0.9); // assume working set memory is 90% of ramsize
313 sg_vm_set_migration_speed(vm, mig_netspeed * 1024 * 1024.0);
315 XBT_DEBUG("migspeed : %f intensity mem : %d", mig_netspeed * 1024 * 1024.0, dp_intensity);
320 int sg_vm_is_migrating(simgrid::s4u::VirtualMachine* vm)
322 return vm->get_impl()->is_migrating_;
325 void sg_vm_migrate(simgrid::s4u::VirtualMachine* vm, simgrid::s4u::Host* dst_pm)
327 simgrid::s4u::Host* src_pm = vm->get_pm();
329 if (src_pm->is_off())
330 THROWF(vm_error, 0, "Cannot migrate VM '%s' from host '%s', which is offline.", vm->get_cname(),
331 src_pm->get_cname());
332 if (dst_pm->is_off())
333 THROWF(vm_error, 0, "Cannot migrate VM '%s' to host '%s', which is offline.", vm->get_cname(), dst_pm->get_cname());
334 if (vm->get_state() != simgrid::s4u::VirtualMachine::state::RUNNING)
335 THROWF(vm_error, 0, "Cannot migrate VM '%s' that is not running yet.", vm->get_cname());
336 if (vm->get_impl()->is_migrating_)
337 THROWF(vm_error, 0, "Cannot migrate VM '%s' that is already migrating.", vm->get_cname());
339 vm->get_impl()->is_migrating_ = true;
340 simgrid::s4u::VirtualMachine::on_migration_start(*vm);
342 std::string rx_name =
343 std::string("__pr_mig_rx:") + vm->get_cname() + "(" + src_pm->get_cname() + "-" + dst_pm->get_cname() + ")";
344 std::string tx_name =
345 std::string("__pr_mig_tx:") + vm->get_cname() + "(" + src_pm->get_cname() + "-" + dst_pm->get_cname() + ")";
347 simgrid::s4u::ActorPtr rx =
348 simgrid::s4u::Actor::create(rx_name.c_str(), dst_pm, simgrid::vm::MigrationRx(vm, dst_pm));
349 simgrid::s4u::ActorPtr tx =
350 simgrid::s4u::Actor::create(tx_name.c_str(), src_pm, simgrid::vm::MigrationTx(vm, dst_pm));
352 vm->extension_set<simgrid::vm::VmMigrationExt>(new simgrid::vm::VmMigrationExt(simgrid::s4u::Actor::self(), rx, tx));
354 /* wait until the migration have finished or on error has occurred */
355 XBT_DEBUG("wait for reception of the final ACK (i.e. migration has been correctly performed");
356 simgrid::s4u::MailboxPtr mbox_ctl = simgrid::s4u::Mailbox::by_name(
357 std::string("__mbox_mig_ctl:") + vm->get_cname() + "(" + src_pm->get_cname() + "-" + dst_pm->get_cname() + ")");
358 delete static_cast<std::string*>(mbox_ctl->get());
362 vm->get_impl()->is_migrating_ = false;
363 simgrid::s4u::VirtualMachine::on_migration_end(*vm);