monitor memory allocation rates in datdog

{
  "viz": "timeseries",
  "requests": [
    {
      "q": "median(-derivative(system.mem.pct_usable{role:nodejs}by{host}*system.mem.total{role:nodejs}by{host}))",
      "style": {
        "width": "thin",
        "palette": "cool"
      },
      "type": "line"
    },
    {
      "q": "ewma_20(-derivative(system.mem.pct_usable{role:nodejs}by{host}*system.mem.total{role:nodejs}by{host}))",
      "style": {
        "width": "thin",
        "palette": "purple"
      },
      "type": "line"
    },
    {
      "q": "ewma_20(-derivative(system.mem.pct_usable{role:nodejs}by{host}*system.mem.total{role:nodejs}by{host}))",
      "style": {
        "width": "thin",
        "palette": "warm"
      },
      "type": "line"
    }
  ],
  "events": [
    {
      "q": "leak"
    }
  ],
  "yaxis": {
    "scale": "pow1",
    "min": -10000
  }
}