The sample's type.
Must be one of the following values:
CPU: A CPU sample type. This is expressed as the app processing CPU time
(including child processes) as reported by process, as a percentage.
MEMORY: A memory usage sample type. This is expressed as the total proportional set size of an app process, in kilobytes.
RX_RATE: The total number of bytes per second (TCP and UDP) that are sent, by app process.
THREADS: A threads sample type. This is expressed as the total number of threads per app process.
TX_RATE: The total number of bytes per second (TCP and UDP) that are received, by app process.