"No value present" when set cluster policy for autoscaling in solr cloud mode

[Cao, Li]

Hi!

I am trying to add a cluster policy to a freshly built 8.3.0 cluster (no 
collection added). I got this error when adding such a cluster policy

{ 
"set-cluster-policy":[{"cores":"<3","nodeset":{"sysprop.rex.node.type":"tlog"}}]}

Basically I want to limit the number of cores for certain machines with a 
special environmental variable value.

But I got this error response:

{
  "responseHeader":{
    "status":400,
    "QTime":144},
  "result":"failure",
  "WARNING":"This response format is experimental.  It is likely to change in 
the future.",
  "error":{
    "metadata":[
      "error-class","org.apache.solr.api.ApiBag$ExceptionWithErrObject",
      "root-error-class","org.apache.solr.api.ApiBag$ExceptionWithErrObject"],
    "details":[{
        "set-cluster-policy":[{
            "cores":"<3",
            "nodeset":{"sysprop.rex.node.type":"tlog"}}],
        "errorMessages":["No value present"]}],
    "msg":"Error in command payload",
    "code":400}}

However, this works:

{ "set-cluster-policy":[{"cores":"<3","node":"#ANY"}]}

I read the autoscaling policy documentations and cannot figure out why. Could 
someone help me on this?

Thanks!

Li