Interacting with a virtualized cluster service

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:

std::shared_ptr<wrench::VirtualizedClusterComputeService> virtualized_cluster_cs;

// Create a VM with 2 cores and 1 GiB of RAM on Host1, which could fail
// if not enough resources are available
auto vm1_name = virtualized_cluster_cs->createVM(2, pow(2,30), "Host1");

// Create a VM with 4 cores and 2 GiB of RAM on Host2 , which could fail
// if not enough resources are available
auto vm2_name = virtualized_cluster_cs->createVM(4, pow(2,31), "Host2");


// Start the first VM on Host1

// Start the second VM on Host2


// Live migrate vm1 to Host3
virtualized_cluster_cs->migrateVM(vm1_name, "Host3");

// Live migrate vm2 to Host4
virtualized_cluster_cs->migrateVM(vm2_name, "Host4");


// Shutdown the VMs

// Destroy the VMs, which releases resources

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 execution controller implementation in examples/workflow_api/basic-examples/virtualized-cluster-bag-of-tasks/TwoTasksAtATimeVirtualizedClusterWMS.cpp for a more complete example.