Slow performance towards vSphere/VMWare when using `kcli list ...` related cmds

Hi @karmab,

We’ve already chatted about this on Slack. Now, I just wanted to create an issue about. To make it more official and to at some point hopefully get it fixed. If possible.

SEEING

Slow performance when listing vm’s, disks and so forth with kcli list ... related cmds. We’re talking about up to and + 1min at times.

I have access to a quite big VMWare environment and can therefore help you troubleshoot this as well as try out different approaches.

LOOKING FOR

That kcli list ... related cmds are reasonably fast. I would say 5-10 secs.

[prziborowski]

Just wanted to comment here as this was linked to the pyvmomi entry. Each time you make a “vm.<something” statement, it is making a request to the server to fetch that “<something>”.

So for example:

        yamlinfo['cpus'] = vm.config.hardware.numCPU
        yamlinfo['memory'] = vm.config.hardware.memoryMB
        yamlinfo['status'] = translation[vm.runtime.powerState]
        yamlinfo['nets'] = []
        yamlinfo['disks'] = []
        if vm.runtime.powerState == "poweredOn":
            yamlinfo['host'] = vm.runtime.host.name
            for nic in vm.guest.net:
                if 'ip' not in yamlinfo and nic.ipAddress:
                    yamlinfo['ip'] = nic.ipAddress[0]
        for entry in vm.config.extraConfig:

This will make 6 requests (vm.config 3 times, vm.runtime 2 times, vm.guest) for VM properties, and depending on the distance between client and server, it could take some time.

This is also why the find function will be much slower than the findvm function because find is fetching the ‘name’ property in a loop as individual requests and findvm is getting the name property when it collects the VM object references.

You could use the property collector’s RetrievePropertiesEx to fetch config, runtime, guest in 1 call. Similarly for list, you could collect additional properties than name to reduce roundtrips:

        vmlist = collectproperties(si, view=view, objtype=vim.VirtualMachine, pathset=['name'], includemors=True)
        for o in vmlist:
            vm = o['obj']
            if vm.summary.runtime.connectionState != 'orphaned' and not vm.config.template:
                if self.filtervms and 'plan' not in [x.key for x in vm.config.extraConfig]:
                    continue
                vms.append(self.info(o['name'], vm=vm))

2 vm.config calls and 1 vm.summary call, for each vm in the list. And then goes into the info function, which does 6 more requests.

[karmab]

opened https://github.com/vmware/pyvmomi/issues/980 to track slowness