AWS::CloudWatch::Alarm MetricDataQuery
The MetricDataQuery
property type specifies the metric data to return, and whether this call is
just retrieving a batch set of data for one metric, or is performing a math expression
on metric data.
Any expression used must return a single time series. For more information, see Metric Math Syntax and Functions in the Amazon CloudWatch User Guide.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "Expression" :
String
, "Id" :String
, "Label" :String
, "MetricStat" :MetricStat
, "Period" :Integer
, "ReturnData" :Boolean
}
YAML
Expression:
String
Id:String
Label:String
MetricStat:MetricStat
Period:Integer
ReturnData:Boolean
Properties
Expression

The math expression to be performed on the returned data, if this object is performing a math expression. This expression can use the
Id
of the other metrics to refer to those metrics, and can also use theId
of other expressions to use the result of those expressions. For more information about metric math expressions, see Metric Math Syntax and Functions in the Amazon CloudWatch User Guide.Within each MetricDataQuery object, you must specify either
Expression
orMetricStat
but not both.Required: No
Type: String
Minimum:
1
Maximum:
1024
Update requires: No interruption
Id

A short name used to tie this object to the results in the response. This name must be unique within a single call to
GetMetricData
. If you are performing math expressions on this set of data, this name represents that data and can serve as a variable in the mathematical expression. The valid characters are letters, numbers, and underscore. The first character must be a lowercase letter.Required: Yes
Type: String
Minimum:
1
Maximum:
255
Update requires: No interruption
Label

A humanreadable label for this metric or expression. This is especially useful if this is an expression, so that you know what the value represents. If the metric or expression is shown in a CloudWatch dashboard widget, the label is shown. If
Label
is omitted, CloudWatch generates a default.Required: No
Type: String
Update requires: No interruption
MetricStat

The metric to be returned, along with statistics, period, and units. Use this parameter only if this object is retrieving a metric and not performing a math expression on returned data.
Within one MetricDataQuery object, you must specify either
Expression
orMetricStat
but not both.Required: No
Type: MetricStat
Update requires: No interruption
Period

The granularity, in seconds, of the returned data points. For metrics with regular resolution, a period can be as short as one minute (60 seconds) and must be a multiple of 60. For highresolution metrics that are collected at intervals of less than one minute, the period can be 1, 5, 10, 30, 60, or any multiple of 60. Highresolution metrics are those metrics stored by a
PutMetricData
operation that includes aStorageResolution of 1 second
.Required: No
Type: Integer
Minimum:
1
Update requires: No interruption
ReturnData

This option indicates whether to return the timestamps and raw data values of this metric.
When you create an alarm based on a metric math expression, specify
True
for this value for only the one math expression that the alarm is based on. You must specifyFalse
forReturnData
for all the other metrics and expressions used in the alarm.This field is required.
Required: No
Type: Boolean
Update requires: No interruption