Add Hyper-V VM Memory metrics

[andbanman]

Add Win32_PerfRawData_BalancerStats_HyperVDynamicMemoryVM WMI class to monitor VM memory. The class shows metrics for VMs with and without dynamic memory enabled.

This partially addresses #574 #517

Example output:

# HELP windows_hyperv_vm_memory_add_operations                                                                                                                                                                                                                                
# TYPE windows_hyperv_vm_memory_add_operations counter                                                                                                                                                                                                                        
windows_hyperv_vm_memory_add_operations{vm="myvm"} 0                                                                                                                                                                                                                          
# HELP windows_hyperv_vm_memory_added                                                                                                                                                                                                                                         
# TYPE windows_hyperv_vm_memory_added counter                                                                                                                                                                                                                                 
windows_hyperv_vm_memory_added{vm="myvm"} 0                                                                                                                                                                                                                                   
# HELP windows_hyperv_vm_memory_physical_guest_visible 'This counter represents the amount of memory visible in the VM.'                                                                                                                                                      
# TYPE windows_hyperv_vm_memory_physical_guest_visible counter                                                                                                                                                                                                                
windows_hyperv_vm_memory_physical_guest_visible{vm="myvm"} 4000                                                                                                                                                                                                               
# HELP windows_hyperv_vm_memory_physical_memory This counter represents the current amount of memory in the VM.                                                                                                                                                               
# TYPE windows_hyperv_vm_memory_physical_memory counter                                                                                                                                                                                                                       
windows_hyperv_vm_memory_physical_memory{vm="myvm"} 4000                                                                                                                                                                                                                      
# HELP windows_hyperv_vm_memory_pressure_average This counter represents the average pressure in the VM.                                                                                                                                                                      
# TYPE windows_hyperv_vm_memory_pressure_average counter                                                                                                                                                                                                                      
windows_hyperv_vm_memory_pressure_average{vm="myvm"} 161                                                                                                                                                                                                                      
# HELP windows_hyperv_vm_memory_pressure_current This counter represents the current pressure in the VM.                                                                                                                                                                      
# TYPE windows_hyperv_vm_memory_pressure_current counter                                                                                                                                                                                                                      
windows_hyperv_vm_memory_pressure_current{vm="myvm"} 161                                                                                                                                                                                                                      
# HELP windows_hyperv_vm_memory_pressure_maximum This counter represents the maximum pressure band in the VM.                                                                                                                                                                 
# TYPE windows_hyperv_vm_memory_pressure_maximum counter                                                                                                                                                                                                                      
windows_hyperv_vm_memory_pressure_maximum{vm="myvm"} 164                                                                                                                                                                                                                      
# HELP windows_hyperv_vm_memory_pressure_minimum This counter represents the minmum pressure band in the VM.                                                                                                                                                                  
# TYPE windows_hyperv_vm_memory_pressure_minimum counter                                                                                                                                                                                                                      
windows_hyperv_vm_memory_pressure_minimum{vm="myvm"} 159                                                                                                                                                                                                                      
# HELP windows_hyperv_vm_memory_remove_operations                                                                                                                                                                                                                             
# TYPE windows_hyperv_vm_memory_remove_operations counter                                                                                                                                                                                                                     
windows_hyperv_vm_memory_remove_operations{vm="myvm"} 0                                                                                                                                                                                                                       
# HELP windows_hyperv_vm_memory_removed                                                                                                                                                                                                                                       
# TYPE windows_hyperv_vm_memory_removed counter                                                                                                                                                                                                                               
windows_hyperv_vm_memory_removed{vm="myvm"} 0

[breed808]

Thanks for submitting this! There's some changes required for the metric names & descriptions, but overall this is looking good 👍

[breed808]

Aside from the review comments, you'll also need to sign off on the commit (see the link next to the failed action for info).

It'd be a good idea to rebase your feature branch to pick up recent CI fixes too.

[breed808]

Thanks, this is looking good. I've added initial documentation entries for the memory metrics as well.

[andbanman]

Thank you for taking the time to review and for the helpful suggestions. I'm working on relevant alerts and a Grafana dashboard that I plan to share soon.