instances_statistics_reference.groovy

// Calculates the sum of all instances metrics and divides by the number of instances (average)
instancesStatistics Statistics.average

// Selects the instance metric with the greatest value (maximum)
instancesStatistics Statistics.maximum

// Selects the instance metric with the smallest value (minimum)
instancesStatistics Statistics.minimum

// Selects the instance metric that is greater than 10% of the other metrics and
// smaller than 90% of the other metrics
instancesStatistics Statistics.percentile(10)

// Selects the instance metric that is greater than 50% of the other metrics
// and smaller than 50% of the other metrics (median)
instancesStatistics Statistics.percentile(50)
instancesStatistics Statistics.median

statistics_reference.groovy

// Shorthand for:
// timeStatistic average
// instancesStatistic average
statistics Statistics.averageOfAverages

// Shorthand for:
// timeStatistic average
// instancesStatistic maximum
statistics Statistics.maximumOfAverages

// Shorthand for:
// timeStatistic average
// instancesStatistic minimum
statistics Statistics.minimumOfAverages
// Shorthand for:
// timeStatistic average
// instancesStatistic percentile(10)
statistics Statistics.percentileOfAverages(10)

// Shorthand for:
// timeStatistic maximum
// instancesStatistic maximum
statistics Statistics.maximumOfMaximums

// Shorthand for:
// timeStatistic minimum
// instancesStatistic minimum
statistics Statistics.minimumOfMinimums


// Shorthand for:
// timeStatistic throughput
// instancesStatistic maximum
statistics Statistics.maximumThroughput

// Shorthand for:
// timeStatistic throughput
// instancesStatistic minimum
statistics Statistics.minimumThroughput

// Shorthand for:
// timeStatistic throughput
// instancesStatistic average
statistics Statistics.averageThroughput

time_window_statistics_reference.groovy

// Calculates the sum all metrics and divides by the number of metrics (average)
// during the specified time window
timeStatistics Statistics.average

// Selects the metric with the greatest value (maximum)
// during the specified time window
timeStatistics Statistics.maximum

// Selects the metric with the smallest value (minimum)
// during the specified time window
timeStatistics Statistics.minimum

// Selects the metric that is greater than 10% of the other metrics and
// smaller than 90% of the other metrics
// during the specified time window
timeStatistics Statistics.percentile(10)

// Selects the metric that is greater than 50% of the other metrics
// and smaller than 50% of the other metrics (median)
// during the specified time window
timeStatistics Statistics.percentile(50)
timeStatistics Statistics.median

// Calculates the average change per second during the specified time window.
// (lastMetric - firstMetric)/(lastMetricSeconds - firstMetricSeconds)
// Here is a throughput calculation example given the total number of requests metric
// during a 20 seconds time window:
// timestamp (seconds)  | value(total number of requests)
//  0                   |  1000
//  5                   |  1200
// 10                   |  1400
// 15                   |  1600
// 20                   |  1800
// The throughput would be (1800-1000)/(20-0)= 1800/20= 90 requests per second
metric "Total Requests Count"
timeStatistics Statistics.throughput

// Calculates the average change per millisecond during the specified time window multiplied by 100.
// 100 * (lastMetric - firstMetric)/(lastMetricMilliseconds - firstMetricMilliseconds)
// The total CPU as provided by Sigar is the total number of milliseconds that the CPU was busy.
// Here is a CPU percentage calculation example given the total CPU:
// timestamp (ms)  | value(total cpu as provided by sigar)
//     0           |  1000
//  5000           |  1200
// 10000           |  1400
// 15000           |  1600
// 20000           |  1800
// The CPU percentage would be 100*(1800 - 1000)/(20000-0)= 100*0.04 = 4
// If you would run top on that machine you would see the figure 4%
metric "Total Process Cpu Time"
timeStatistics Statistics.averageCpuPercentage

tomcat_auto_scaling.groovy

service {
  name "tomcat"
  ...
				
  /* A global flag that enables changing the number of 
     instances for this service */
  elastic true

  // the initial number of instances
  numInstances 1

  /* The minimum number of service instances.
    Used together with scaling rules */
  minAllowedInstances 1

  /* The maximum number of service instances.
    Used together with scaling rules */
  maxAllowedInstances 2

  /* The time (in seconds) that scaling rules are disabled after
     scale in (instances removed) or scale out (instances added).
     This has the same effect as setting scaleInCooldownInSeconds 
     and scaleOutCooldownInSeconds separately.	
    Used together with scaling rules.
    This attribute should be greater than or equal 
    to the movingTimeRangeInSeconds attribute 
    in the serviceStatistics section.
  */
  scaleCooldownInSeconds 20

  /* The time (in seconds) between two consecutive metric samples.
    Used together with scaling rules */
  samplingPeriodInSeconds 1

  // Defines an automatic scaling rule based on "counter" metric value
  scalingRules ([
    scalingRule {
      serviceStatistics {
        /* The name of the metric that is the basis
           for the scale rule decision
           In the current example, the metric we use is "Total Requests Count".
         */
	metric "Total Requests Count"

        /* (Optional)
	   The sliding time range (in seconds) for
	   aggregating per-instance metric samples.
	   The number of samples in the time windows equals
	   the time window divided by the sampling period.
	   Default value: 300 */
	movingTimeRangeInSeconds 20

        /* (Optional)
           The algorithms for aggregating metric samples by instances 
           and by time. Metric samples are aggregated separately 
           per instance in the specified time range,and then aggregated 
           again for all instances.
           Default value: Statistics.averageOfAverages
           Possible values: 
             Statistics.maximumOfAverages, 
             Statistics.minimumOfAverages, 
             Statistics.averageOfAverages,
             Statistics.percentileOfAverages(90),
             Statistics.maximumOfMaximums, 
             Statistics.minimumOfMinimums, 
             Statistics.maximumThroughput.
		 
         The following has the same effect as setting instancesStatistics 
           and timeStatistics separately.
           For example: 
            statistics Statistics.maximumOfAverages
           is the same as:
            timeStatistics Statistics.average
            instancesStatistics Statistics.maximum */

        statistics Statistics.maximumThroughput

      }


      highThreshold {
        /* The value above which the number of instances is increased */
        value 1

        /* The number of instances to increase when above threshold */
	instancesIncrease 1
      }

      lowThreshold {
        /* The value below which the number of instances is decreased */
        value 0.2
		  
	/* The number of instances to decrease when below threshold */
	instancesDecrease 1
      }
    }
  ])

  plugins([
    plugin {
      name "jmx"
      className "org.cloudifysource.usm.jmx.JmxMonitor"
      config([						
        "Total Requests Count": [ 
          "Catalina:type=GlobalRequestProcessor,name=\"http-bio-8080\"",
          "requestCount"
        ],

	port: "11099"
     ])
    }
  ])
}