Interacting with a virtualized cluster service {#guide-102-virtualizedcluster}

The wrench::VirtualizedClusterComputeService derives the wrench::CloudComputeService class. One interacts with it in almost the same way as one interacts with a cloud servicde. The one difference between a virtualized cluster service and a cloud service is that the former exposes underlying physical resources, while the latter does not. More simply put, with a virtualized cluster service one can create VM instances on specific hosts, and migrate VM instances between hosts.

Here is an example interaction with a virtualized cluster service, in which VM instances are created and (live) migrated:

// Get the first virtualized cluster compute service (assuming there's at least one)
auto virtualized_cluster_cs = *(this->getAvailableComputeServices<wrench::VirtualizedClusterComputeService>().begin());

// Create a VM with 2 cores and 1 GiB of RAM
auto vm1 = virtualized_cluster_cs->createVM(2, pow(2,30));

// Create a VM with 4 cores and 2 GiB of RAM
auto vm2 = virtualized_cluster_cs->createVM(4, pow(2,31));


// Start the first VM on Host1
virtualized_cluster_cs->startVM(vm1, "Host1");

// Start the second VM on Host2
virtualized_cluster_cs->startVM(vm1, "Host2");


// Live migrate vm1 to host3
virtualized_cluster_cs->migrateVM(vm1, "host3");

// Live migrate vm2 to host4
virtualized_cluster_cs->migrateVM(vm2, "host4");


// Shutdown the VMs

In the code above the VM instances are not used for anything. See the interacting with a cloud service page for an example in which jobs are submitted to the VM instances.

See the WMS implementation in examples/basic-examples/virtualized-cluster-bag-of-tasks/TwoTasksAtATimeVirtualizedClusterWMS.cpp for a more complete example.