This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::ApplicationSignals::ServiceLevelObjective
<a name="aws-resource-applicationsignals-servicelevelobjective"></a>

Creates or updates a service level objective (SLO), which can help you ensure that your critical business operations are meeting customer expectations. Use SLOs to set and track specific target levels for the reliability and availability of your applications and services. SLOs use service level indicators (SLIs) to calculate whether the application is performing at the level that you want.

Create an SLO to set a target for a service operation, or service dependency's availability or latency. CloudWatch measures this target frequently you can find whether it has been breached.

The target performance quality that is defined for an SLO is the *attainment goal*. An attainment goal is the percentage of time or requests that the SLI is expected to meet the threshold over each time interval. For example, an attainment goal of 99.9% means that within your interval, you are targeting 99.9% of the periods to be in healthy state.

When you create an SLO, you specify whether it is a *period-based SLO* or a *request-based SLO*. Each type of SLO has a different way of evaluating your application's performance against its attainment goal.
+ A *period-based SLO* uses defined *periods* of time within a specified total time interval. For each period of time, Application Signals determines whether the application met its goal. The attainment rate is calculated as the `number of good periods/number of total periods`.

  For example, for a period-based SLO, meeting an attainment goal of 99.9% means that within your interval, your application must meet its performance goal during at least 99.9% of the time periods.
+ A *request-based SLO* doesn't use pre-defined periods of time. Instead, the SLO measures `number of good requests/number of total requests` during the interval. At any time, you can find the ratio of good requests to total requests for the interval up to the time stamp that you specify, and measure that ratio against the goal set in your SLO.

After you have created an SLO, you can retrieve error budget reports for it. An *error budget* is the amount of time or amount of requests that your application can be non-compliant with the SLO's goal, and still have your application meet the goal.
+ For a period-based SLO, the error budget starts at a number defined by the highest number of periods that can fail to meet the threshold, while still meeting the overall goal. The *remaining error budget* decreases with every failed period that is recorded. The error budget within one interval can never increase.

  For example, an SLO with a threshold that 99.95% of requests must be completed under 2000ms every month translates to an error budget of 21.9 minutes of downtime per month.
+ For a request-based SLO, the remaining error budget is dynamic and can increase or decrease, depending on the ratio of good requests to total requests.

When you call this operation, Application Signals creates the *AWSServiceRoleForCloudWatchApplicationSignals* service-linked role, if it doesn't already exist in your account. This service- linked role has the following permissions:
+  `xray:GetServiceGraph` 
+  `logs:StartQuery` 
+  `logs:GetQueryResults` 
+  `cloudwatch:GetMetricData` 
+  `cloudwatch:ListMetrics` 
+  `tag:GetResources` 
+  `autoscaling:DescribeAutoScalingGroups` 

You can easily set SLO targets for your applications, and their dependencies, that are discovered by Application Signals, using critical metrics such as latency and availability. You can also set SLOs against any CloudWatch metric or math expression that produces a time series.

**Note**  
You can't create an SLO for a service operation that was discovered by Application Signals until after that operation has reported standard metrics to Application Signals.

You cannot change from a period-based SLO to a request-based SLO, or change from a request-based SLO to a period-based SLO.

For more information about SLOs, see [ Service level objectives (SLOs)](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-ServiceLevelObjectives.html). 

## Syntax
<a name="aws-resource-applicationsignals-servicelevelobjective-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-applicationsignals-servicelevelobjective-syntax.json"></a>

```
{
  "Type" : "AWS::ApplicationSignals::ServiceLevelObjective",
  "Properties" : {
      "[BurnRateConfigurations](#cfn-applicationsignals-servicelevelobjective-burnrateconfigurations)" : [ BurnRateConfiguration, ... ],
      "[Description](#cfn-applicationsignals-servicelevelobjective-description)" : String,
      "[ExclusionWindows](#cfn-applicationsignals-servicelevelobjective-exclusionwindows)" : [ ExclusionWindow, ... ],
      "[Goal](#cfn-applicationsignals-servicelevelobjective-goal)" : Goal,
      "[Name](#cfn-applicationsignals-servicelevelobjective-name)" : String,
      "[RequestBasedSli](#cfn-applicationsignals-servicelevelobjective-requestbasedsli)" : RequestBasedSli,
      "[Sli](#cfn-applicationsignals-servicelevelobjective-sli)" : Sli,
      "[Tags](#cfn-applicationsignals-servicelevelobjective-tags)" : [ Tag, ... ]
    }
}
```

### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective-syntax.yaml"></a>

```
Type: AWS::ApplicationSignals::ServiceLevelObjective
Properties:
  [BurnRateConfigurations](#cfn-applicationsignals-servicelevelobjective-burnrateconfigurations): 
    - BurnRateConfiguration
  [Description](#cfn-applicationsignals-servicelevelobjective-description): String
  [ExclusionWindows](#cfn-applicationsignals-servicelevelobjective-exclusionwindows): 
    - ExclusionWindow
  [Goal](#cfn-applicationsignals-servicelevelobjective-goal): 
    Goal
  [Name](#cfn-applicationsignals-servicelevelobjective-name): String
  [RequestBasedSli](#cfn-applicationsignals-servicelevelobjective-requestbasedsli): 
    RequestBasedSli
  [Sli](#cfn-applicationsignals-servicelevelobjective-sli): 
    Sli
  [Tags](#cfn-applicationsignals-servicelevelobjective-tags): 
    - Tag
```

## Properties
<a name="aws-resource-applicationsignals-servicelevelobjective-properties"></a>

`BurnRateConfigurations`  <a name="cfn-applicationsignals-servicelevelobjective-burnrateconfigurations"></a>
Each object in this array defines the length of the look-back window used to calculate one burn rate metric for this SLO. The burn rate measures how fast the service is consuming the error budget, relative to the attainment goal of the SLO.  
*Required*: No  
*Type*: Array of [BurnRateConfiguration](aws-properties-applicationsignals-servicelevelobjective-burnrateconfiguration.md)  
*Minimum*: `0`  
*Maximum*: `10`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Description`  <a name="cfn-applicationsignals-servicelevelobjective-description"></a>
An optional description for this SLO.  
*Required*: No  
*Type*: String  
*Minimum*: `1`  
*Maximum*: `1024`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`ExclusionWindows`  <a name="cfn-applicationsignals-servicelevelobjective-exclusionwindows"></a>
The time window to be excluded from the SLO performance metrics.  
*Required*: No  
*Type*: Array of [ExclusionWindow](aws-properties-applicationsignals-servicelevelobjective-exclusionwindow.md)  
*Minimum*: `0`  
*Maximum*: `10`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Goal`  <a name="cfn-applicationsignals-servicelevelobjective-goal"></a>
This structure contains the attributes that determine the goal of an SLO. This includes the time period for evaluation and the attainment threshold.  
*Required*: No  
*Type*: [Goal](aws-properties-applicationsignals-servicelevelobjective-goal.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Name`  <a name="cfn-applicationsignals-servicelevelobjective-name"></a>
A name for this SLO.  
*Required*: Yes  
*Type*: String  
*Pattern*: `^[0-9A-Za-z][-._0-9A-Za-z ]{0,126}[0-9A-Za-z]$`  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`RequestBasedSli`  <a name="cfn-applicationsignals-servicelevelobjective-requestbasedsli"></a>
A structure containing information about the performance metric that this SLO monitors, if this is a request-based SLO.  
*Required*: No  
*Type*: [RequestBasedSli](aws-properties-applicationsignals-servicelevelobjective-requestbasedsli.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Sli`  <a name="cfn-applicationsignals-servicelevelobjective-sli"></a>
A structure containing information about the performance metric that this SLO monitors, if this is a period-based SLO.  
*Required*: No  
*Type*: [Sli](aws-properties-applicationsignals-servicelevelobjective-sli.md)  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`Tags`  <a name="cfn-applicationsignals-servicelevelobjective-tags"></a>
A list of key-value pairs to associate with the SLO. You can associate as many as 50 tags with an SLO. To be able to associate tags with the SLO when you create the SLO, you must have the cloudwatch:TagResource permission.  
Tags can help you organize and categorize your resources. You can also use them to scope user permissions by granting a user permission to access or change only resources with certain tag values.  
*Required*: No  
*Type*: Array of [Tag](aws-properties-applicationsignals-servicelevelobjective-tag.md)  
*Minimum*: `1`  
*Maximum*: `200`  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

## Return values
<a name="aws-resource-applicationsignals-servicelevelobjective-return-values"></a>

### Ref
<a name="aws-resource-applicationsignals-servicelevelobjective-return-values-ref"></a>

When you pass the logical ID of this resource to the intrinsic `Ref` function, `Ref` returns the ARN of the SLO. For example, `arn:aws:cloudwatch:us-west-1:123456789012:slo:my-slo-name`

### Fn::GetAtt
<a name="aws-resource-applicationsignals-servicelevelobjective-return-values-fn--getatt"></a>

#### 
<a name="aws-resource-applicationsignals-servicelevelobjective-return-values-fn--getatt-fn--getatt"></a>

`Arn`  <a name="Arn-fn::getatt"></a>
The ARN of this SLO.

`CreatedTime`  <a name="CreatedTime-fn::getatt"></a>
The date and time that this SLO was created.

`EvaluationType`  <a name="EvaluationType-fn::getatt"></a>
Displays whether this is a period-based SLO or a request-based SLO.

`LastUpdatedTime`  <a name="LastUpdatedTime-fn::getatt"></a>
The time that this SLO was most recently updated.

## Examples
<a name="aws-resource-applicationsignals-servicelevelobjective--examples"></a>



**Topics**
+ [A period-based SLO on service dependency latency](#aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_dependency_latency)
+ [A request-based SLO on service dependency latency](#aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_service_dependency_latency)
+ [A period-based SLO on service operation latency](#aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_latency)
+ [A period-based SLO on service operation availability](#aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_availability)
+ [A period-based SLO on CloudWatch metrics](#aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_CloudWatch_metrics)
+ [A request-based SLO on CloudWatch metrics](#aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_CloudWatch_metrics)

### A period-based SLO on service dependency latency
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_dependency_latency"></a>

The following example creates a period-based SLO on service dependency latency.

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_dependency_latency--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Sample period-based latency slo with dependency config."
      Sli:
        SliMetric:
          KeyAttributes:
            Environment: "eks:pet-clinic-slo-canary/default"
            Name: "TestServiceForCloudFormation-1"
            Type: "Service"
          OperationName: "Operation-1"
          MetricType: "LATENCY"
          Statistic: "p99"
          PeriodSeconds: 60
          DependencyConfig:
            DependencyKeyAttributes:
              Identifier: "sample_kinesis_stream"
              ResourceType: "AWS::Kinesis::Stream"
              Type: "AWS::Resource"
            DependencyOperationName: "Operation-1"
        MetricThreshold: 2.5
        ComparisonOperator: "LessThanOrEqualTo"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```

### A request-based SLO on service dependency latency
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_service_dependency_latency"></a>

The following example creates a request-based SLO on service dependency availability. 

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_service_dependency_latency--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Sample request-based availability slo with dependency config."
      RequestBasedSli:
        RequestBasedSliMetric:
          KeyAttributes:
            Environment: "eks:pet-clinic-slo-canary/default"
            Name: "TestServiceForCloudFormation-1"
            Type: "Service"
          OperationName: "Operation-1"
          MetricType: "AVAILABILITY"
          DependencyConfig:
            DependencyKeyAttributes:
              Identifier: "sample_kinesis_stream"
              ResourceType: "AWS::Kinesis::Stream"
              Type: "AWS::Resource"
            DependencyOperationName: "Operation-1"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```

### A period-based SLO on service operation latency
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_latency"></a>

The following example creates a period-based SLO on service operation latency.

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_latency--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Canary test custom-metric slo description."
      Sli:
        SliMetric:
          KeyAttributes:
            Environment: "eks:pet-clinic-slo-canary/default"
            Name: "TestServiceForCloudFormation-1"
            Type: "Service"
          OperationName: "Operation-1"
          MetricType: "LATENCY"
          Statistic: "p99"
          PeriodSeconds: 60
        MetricThreshold: 2.5
        ComparisonOperator: "LessThanOrEqualTo"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```

### A period-based SLO on service operation availability
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_availability"></a>

The following example creates a period-based SLO on service operation availability.

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_service_operation_availability--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Canary test custom-metric slo description."
      Sli:
        SliMetric:
          KeyAttributes:
            Environment: "eks:pet-clinic-slo-canary/default"
            Name: "TestServiceForCloudFormation-1"
            Type: "Service"
          OperationName: "Operation-1"
          MetricType: "AVAILABILITY"
          PeriodSeconds: 60
        MetricThreshold: 2.5
        ComparisonOperator: "LessThanOrEqualTo"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```

### A period-based SLO on CloudWatch metrics
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_CloudWatch_metrics"></a>

The following example creates a period-based SLO on CloudWatch metrics.

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_period-based_SLO_on_CloudWatch_metrics--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Canary test custom-metric slo description."
      Sli:
        SliMetric:
          MetricDataQueries:
            - MetricStat:
                Period: 60
                Metric:
                  MetricName: "Latency"
                  Dimensions:
                    - Value: "Operation-1"
                      Name: "Operation"
                    - Value: "TestServiceForCloudFormation-1"
                      Name: "Service"
                    - Value: "eks:pet-clinic-slo-canary/default"
                      Name: "Environment"
                  Namespace: "ApplicationSignals"
                Stat: "p99"
                Unit: "Milliseconds"
              Id: "latency"
              ReturnData: false
            - Id: "latencyfinal"
              ReturnData: true
              Expression: "latency * 1"
        MetricThreshold: 2.5
        ComparisonOperator: "LessThanOrEqualTo"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```

### A request-based SLO on CloudWatch metrics
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_CloudWatch_metrics"></a>

The following example creates a request-based SLO on CloudWatch metrics.

#### YAML
<a name="aws-resource-applicationsignals-servicelevelobjective--examples--A_request-based_SLO_on_CloudWatch_metrics--yaml"></a>

```
Resources:
  ServiceLevelObjective:
    Type: AWS::ApplicationSignals::ServiceLevelObjective
    Properties:
      Name: !Join ["-", ["CanaryTestSlo", !Select [2, !Split ['/', !Ref AWS::StackId]]]]
      Description: "Canary test request-based slo description."
      RequestBasedSli:
        RequestBasedSliMetric:
          TotalRequestCountMetric:
            - MetricStat:
                Period: 60
                Metric:
                  MetricName: "Latency"
                  Dimensions:
                    - Value: "Operation-1"
                      Name: "Operation"
                    - Value: "TestServiceForCloudFormation-1"
                      Name: "Service"
                    - Value: "eks:pet-clinic-slo-canary/default"
                      Name: "Environment"
                  Namespace: "ApplicationSignals"
                Stat: "SampleCount"
                Unit: "Milliseconds"
              Id: "totalCount"
              ReturnData: false
            - Id: "totalCountFinal"
              ReturnData: true
              Expression: "totalCount * 1" 
          MonitoredRequestCountMetric:
            GoodCountMetric:
              - MetricStat:
                  Period: 60
                  Metric:
                    MetricName: "Latency"
                    Dimensions:
                      - Value: "Operation-1"
                        Name: "Operation"
                      - Value: "TestServiceForCloudFormation-1"
                        Name: "Service"
                      - Value: "eks:pet-clinic-slo-canary/default"
                        Name: "Environment"
                    Namespace: "ApplicationSignals"
                  Stat: "SampleCount"
                  Unit: "Milliseconds"
                Id: "goodCount"
                ReturnData: false
              - Id: "goodCountFinal"
                ReturnData: true
                Expression: "goodCount - 1"
      Goal:
        Interval:
          RollingInterval:
            DurationUnit: "DAY"
            Duration: 1
        AttainmentGoal: 90.0
        WarningThreshold: 80.0
```