JMX input filter, howto construct right query

So I've got a jconsole on a cassandra 2.0 cluster and can see metrics like o.a.c.m.ThreadPools.request.RequestResponseStage.*Tasks

cassandra wiki says (note ThreadPool in singular):

o.a.c.m:type=ThreadPool,path=(type),scope=(Thread pool name),name=(Metric name)
(path) is either internal or request, based on the usage of thread pool
(scope) is (path).(Thread pool name)
(name) is one of the five Tasks, ie. ActiveTasks...

But how should I read this to configure my jmx input query's json to fetch such metric, below doesn't work:

"object_name" : "org.apache.cassandra.metrics:type=ThreadPools,path=request,scope=RequestResponseStage,name=*",
"attributes" : [ "ActiveTasks", "CompletedTasks", "CurrentlyBlockedTasks", "PendingTasks", "TotalBlockedTasks" ],
"object_alias" : "${type}.${path}.${scope}.${name}"

It returns this warning:

undefined method `active_tasks' for #JMX::MBean:0x553f7ee2 {:level=>:warn}
Failed retrieving metrics for attribute ActiveTasks on object org.apache.cassandra.metrics:type=ThreadPools,path=request,scope=RequestResponseStage,name=ActiveTasks {:level=>:warn}

Though one would believe this to be correct when looking at the jconsole

Other metric fetches fine, and return events as expected like:

"@version" => "1",
"@timestamp" => "2015-12-10T23:19:20.791Z",
"host" => "d1r1n1",
"type" => "jmx",
"metric_path" => "",
"metric_value_string" => "java.nio:type=BufferPool,name=direct",
"@metadata" => {
"esindex" => "cass",
"output-stdout" => "true"

Hints much appreciated, TIA!

Connected a Console and browsed the MBeans and found that this works:

"object_name" : "org.apache.cassandra.metrics:type=ThreadPools,path=request,scope=RequestResponseStage,name=*",
"object_alias" : "${type}.${path}.${scope}.${name}"