Hi,
You need to add them when you create nodes via SDK. Also provide values for below provided properties for proper polling.
'BufferNoMemThisHour' => -2,
'BufferNoMemToday' => -2,
'BufferSmMissThisHour' => -2,
'BufferSmMissToday' => -2,
'BufferMdMissThisHour' => -2,
'BufferMdMissToday' => -2,
'BufferBgMissThisHour' => -2,
'BufferBgMissToday' => -2,
'BufferLgMissThisHour' => -2,
'BufferLgMissToday' => -2,
'BufferHgMissThisHour' => -2,
'BufferHgMissToday' => -2,
'PercentMemoryUsed' => -2,
'TotalMemory' => -2,