Interacting with a virtualized cluster service
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 virtualized_cluster_cs->startVM(vm1_name); // Start the second VM on Host2 virtualized_cluster_cs->startVM(vm2_name); [...] // 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 virtualized_cluster_cs->shutdownVM(vm1_name); virtualized_cluster_cs->shutdownVM(vm2_name); // Destroy the VMs, which releases resources virtualized_cluster_cs->destroyVM(vm1_name); virtualized_cluster_cs->destroyVM(vm2_name);
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
for a more complete example.