R/autoscale.R

In Azure/doAzureParallel: doAzureParallel

autoscaleWorkdayFormula <- paste0(
  "$curTime = time();",
  "$workHours = $curTime.hour >= 8 && $curTime.hour < 18;",
  "$isWeekday = $curTime.weekday >= 1 && $curTime.weekday <= 5;",
  "$isWorkingWeekdayHour = $workHours && $isWeekday;",
  "$TargetDedicatedNodes = $isWorkingWeekdayHour ? %s:%s;"
)

autoscaleWeekendFormula <- paste0(
  "$isWeekend = $curTime.weekday >= 6 && $curTime.weekday <= 7;",
  "$TargetDedicatedNodes = $isWeekend ? %s:%s;"
)

autoscaleMaxCpuFormula <- paste0(
  "$totalNodes = (min($CPUPercent.GetSample(TimeInterval_Minute * 10)) > 0.7) ? ",
  "($CurrentDedicated * 1.1) : $CurrentDedicated; $totalNodes = ",
  "(avg($CPUPercent.GetSample(TimeInterval_Minute * 60)) < 0.2) ? ",
  "($CurrentDedicated * 0.9) : $totalNodes; ",
  "$TargetDedicatedNodes = min(%s, $totalNodes)"
)

autoscaleQueueFormula <- paste0(
  "$samples = $ActiveTasks.GetSamplePercent(TimeInterval_Minute * 15);",
  "$tasks = $samples < 70 ? max(0,$ActiveTasks.GetSample(1)) : ",
  "max( $ActiveTasks.GetSample(1), avg($ActiveTasks.GetSample(TimeInterval_Minute * 15)));",
  "$maxTasksPerNode = %s;",
  "$round = $maxTasksPerNode - 1;",
  "$targetVMs = $tasks > 0 ? (($tasks + $round) / $maxTasksPerNode) : max(0, $TargetDedicated/2) + 0.5;",
  "$TargetDedicatedNodes = max(%s, min($targetVMs, %s));",
  "$TargetLowPriorityNodes = max(%s, min($targetVMs, %s));",
  "$NodeDeallocationOption = taskcompletion;"
)

autoscaleQueueAndRunningFormula <- paste0(
  "$samples = $PendingTasks.GetSamplePercent(TimeInterval_Minute * 15);",
  "$tasks = $samples < 70 ? max(0,$PendingTasks.GetSample(1)) : ",
  "max( $PendingTasks.GetSample(1), avg($PendingTasks.GetSample(TimeInterval_Minute * 15)));",
  "$maxTasksPerNode = %s;",
  "$round = $maxTasksPerNode - 1;",
  "$targetVMs = $tasks > 0 ? (($tasks + $round) / $maxTasksPerNode) : max(0, $TargetDedicated/2) + 0.5;",
  "$TargetDedicatedNodes = max(%s, min($targetVMs, %s));",
  "$TargetLowPriorityNodes = max(%s, min($targetVMs, %s));",
  "$NodeDeallocationOption = taskcompletion;"
)

autoscaleFormula <- list(
  "WEEKEND" = autoscaleWeekendFormula,
  "WORKDAY" = autoscaleWorkdayFormula,
  "MAX_CPU" = autoscaleMaxCpuFormula,
  "QUEUE" = autoscaleQueueFormula,
  "QUEUE_AND_RUNNING" = autoscaleQueueAndRunningFormula
)

getAutoscaleFormula <-
  function(formulaName,
           dedicatedMin,
           dedicatedMax,
           lowPriorityMin,
           lowPriorityMax,
           maxTasksPerNode = 1) {
    formulas <- names(autoscaleFormula)

    if (formulaName == formulas[1]) {
      return(sprintf(autoscaleWeekendFormula, dedicatedMin, dedicatedMax))
    }
    else if (formulaName == formulas[2]) {
      return(sprintf(autoscaleWorkdayFormula, dedicatedMin, dedicatedMax))
    }
    else if (formulaName == formulas[3]) {
      return(sprintf(autoscaleMaxCpuFormula, dedicatedMin))
    }
    else if (formulaName == formulas[4]) {
      return(
        sprintf(
          autoscaleQueueFormula,
          maxTasksPerNode,
          dedicatedMin,
          dedicatedMax,
          lowPriorityMin,
          lowPriorityMax
        )
      )
    }
    else if (formulaName == formulas[5]) {
      return(
        sprintf(
          autoscaleQueueAndRunningFormula,
          maxTasksPerNode,
          dedicatedMin,
          dedicatedMax,
          lowPriorityMin,
          lowPriorityMax
        )
      )
    }
    else{
      stop("Incorrect autoscale formula: QUEUE, QUEUE_AND_RUNNING, MAX_CPU, WEEKEND, WORKDAY")
    }
  }

#' Resize an Azure cloud-enabled cluster.
#'
#' @param cluster Cluster object that was referenced in \code{makeCluster}
#' @param dedicatedMin The minimum number of dedicated nodes
#' @param dedicatedMax The maximum number of dedicated nodes
#' @param lowPriorityMin The minimum number of low priority nodes
#' @param lowPriorityMax The maximum number of low priority nodes
#' @param algorithm Current built-in autoscale formulas: QUEUE, MAX_CPU, WEEKEND, WEEKDAY
#' @param timeInterval Time interval at which to automatically adjust the pool size according to the autoscale formula
#'
#' @examples
#' \dontrun{
#' resizeCluster(cluster, dedicatedMin = 2, dedicatedMax = 6,
#'              lowPriorityMin = 2, lowPriorityMax = 6, algorithm = "QUEUE", timeInterval = "PT10M")
#' }
#' @export
resizeCluster <- function(cluster,
                          dedicatedMin,
                          dedicatedMax,
                          lowPriorityMin,
                          lowPriorityMax,
                          algorithm = "QUEUE",
                          timeInterval = "PT5M") {
  config <- getOption("az_config")

  # Use the Pool GET API to get the correct pool properties: MaxTaskPerNodes
  cluster <- config$batchClient$poolOperations$getPool(
    cluster$poolId)

  config$batchClient$poolOperations$resizePool(
    cluster$id,
    autoscaleFormula = getAutoscaleFormula(
      algorithm,
      dedicatedMin,
      dedicatedMax,
      lowPriorityMin,
      lowPriorityMax,
      maxTasksPerNode = cluster$maxTasksPerNode
    ),
    autoscaleInterval = timeInterval
  )

  print("Cluster autoscale formula has been updated. Run 'getCluster' for updated target node count.")
}