Tuesday, August 20, 2013

Best Practices for Faster vSphere SDK Scripts

Reuben Stump published excellent blog post at http://www.virtuin.com/2012/11/best-practices-for-faster-vsphere-sdk.html about performance optimization of PERL SDK Scripts.

The main takeaway is to minimize the ManagedEntity's Property Set.

So instead of

my $vm_views = Vim::find_entity_views(view_type => "VirtualMachine") ||
  die "Failed to get VirtualMachines: $!";

you have to use

# Fetch all VirtualMachines from SDK, limiting the property set
my $vm_views = Vim::find_entity_views(view_type => "VirtualMachine",
          properties => ['name', 'runtime.host', 'datastore']) ||
  die "Failed to get VirtualMachines: $!";

This small improvement have significant impact on performance because it eliminates big data (SOAP/XML) generation and transfer between vCenter service and the SDK script.

It helped me improve performance of my script from 25 seconds to just 1 second. And the impact is even better for bigger vSphere environment. So my old version of script was almost useless and this simple improvement help me so much.

Thanks Reuben for sharing this information.

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