I checked what kind of CloudWatch alarms are configured when setting up CloudWatch Application Insights for an ECS cluster in Container Insights
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I want to check what CloudWatch alarms are set when configuring CloudWatch Application Insights for ECS
Hello, this is nonPi (@non____97).
Have you ever wondered what CloudWatch alarms are set when configuring CloudWatch Application Insights for ECS? I have.
As introduced in the article below, you can easily enable CloudWatch Application Insights from the Container Insights console.
By setting up Application Insights, you can easily configure application dashboards and alarms, as well as manage events.
So what kind of alarms are set? I couldn't find any documentation about what alarms are set, so I checked it myself.
Summary
- CloudWatch Alarms set when configuring CloudWatch Application Insights for ECS
- ALB's
HTTPCode_Target_4XX_Count - ALB's
HTTPCode_Target_5XX_Count - ECS cluster's
MemoryUtilized - ECS cluster's
CpuUtilized
- ALB's
My Investigation
Test Environment
Here's my test environment.
I'm reusing what I used in the article below.
The code is stored in the following repository.
Enabling CloudWatch Application Insights
I'll enable Application Insights.
This is done from the Container Insights console.
When I checked the Application Insights tab, it displayed "Application monitoring has been successfully enabled. It will take some time for results to appear. Use the refresh button to view results."
I clicked "Auto-configure Application Insights" to enable it.
It appears to be enabled.
Checking the Application Insights Dashboard
After a while, I could see the issues that occurred as shown below. It seems to be about 4XX errors returned by the backend.
When I checked the Application Insights console, I could confirm the same content.
Selecting the application from Applications, I could see the Application Insights dashboard as shown below.
There are about four alarms set, and one is in alarm state.
The dashboard shows CPU and memory usage metrics.
When I clicked the Container Insights link "ALB: Backend 4XX errors", I saw the following screen.
For reference, clicking "Edit" shows the following screen.
Checking Components
Let's check the components.
The type appears to be an ECS cluster. I clicked the component and workload links.
I could see the dashboard as shown below.
I clicked the Resources tab. The ECS service seems to be registered as a resource.
When I selected it and clicked "View details", the ECS service was displayed.
The Monitored Workloads, Logs, Metrics, and Alarms tabs are as follows:
Managing Component Monitoring
I'll edit the metrics handled in the component monitoring. I clicked "Manage component monitoring".
The screen below allows me to manage the monitored metrics and set custom alarms.
For component metrics, I can select either built-in metrics or metrics available through Container Insights.
ALB metrics can also be selected as shown below.
This time, I added TaskCount and ActiveConnectionCount and clicked "Save".
Then, when I checked the metrics selection list from "Add or remove metrics" in the dashboard, I could see the metrics I just added.
When I added the metrics, they were reflected in the dashboard as shown below.
Checking Configuration History
I checked the Configuration History tab.
| Resource | Status | Creation Date | Details |
|---|---|---|---|
| CLOUDWATCH_ALARM | Info | January 17, 2026, 23:36 (UTC+09:00) | Not enough data to predict the threshold. Metric : TargetResponseTime. Component: arn:aws:elasticloadbalancing:us-east-1:<AWSAccountID>:loadbalancer/app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c |
| CLOUDWATCH_METRIC | Info | January 17, 2026, 23:36 (UTC+09:00) | Metric UnHealthyHostCount does not exist for component arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg, subcomponent arn:aws:elasticloadbalancing:us-east-1:<AWSAccountID>:loadbalancer/app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c, alarm cannot be created. Possible reason might be metric misses data points for two weeks, or required workload to emit this metric not installed. |
| CLOUDWATCH_METRIC | Info | January 17, 2026, 23:36 (UTC+09:00) | Metric PendingTaskCount does not exist for component arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg, alarm cannot be created. Possible reason might be metric misses data points for two weeks, or required workload to emit this metric not installed. |
| CLOUDWATCH_ALARM | Info | January 17, 2026, 23:36 (UTC+09:00) | Not enough data to predict the threshold. Metric : StorageReadBytes. Component: arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg |
| SNS_NOTIFICATIONS | Info | January 17, 2026, 23:36 (UTC+09:00) | Problem notifications aren't enabled. Notifications can be enabled on the application edit page. |
| CLOUDWATCH_ALARM | Info | January 17, 2026, 23:36 (UTC+09:00) | Not enough data to predict the threshold. Metric : NetworkTxBytes. Component: arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg |
| CLOUDWATCH_METRIC | Info | January 17, 2026, 23:36 (UTC+09:00) | Metric RunningTaskCount does not exist for component arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg, alarm cannot be created. Possible reason might be metric misses data points for two weeks, or required workload to emit this metric not installed. |
| CLOUDWATCH_ALARM | Info | January 17, 2026, 23:36 (UTC+09:00) | Not enough data to predict the threshold. Metric : StorageWriteBytes. Component: arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg |
| CLOUDWATCH_ALARM | Info | January 17, 2026, 23:36 (UTC+09:00) | Not enough data to predict the threshold. Metric : NetworkRxBytes. Component: arn:aws:ecs:us-east-1:<AWSAccountID>:cluster/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg |
There are several resources with "Not enough data to predict the threshold. Metric" for CLOUDWATCH_ALARM.
The target metrics are:
- ALB's
TargetResponseTime - ECS cluster's
StorageReadBytes - ECS cluster's
StorageWriteBytes - ECS cluster's
NetworkTxBytes - ECS cluster's
NetworkRxBytes
These weren't in the CloudWatch alarms I checked later.
Based on the message, I thought it might be trying to set up CloudWatch Anomaly Detection, but I couldn't find any evidence in CloudTrail that it was trying to create such CloudWatch alarms.
Checking Log Patterns
No log patterns are set.
Checking CloudWatch Alarms
Let's check the CloudWatch alarms.
Looking at CloudWatch Alarms, four are set as follows:
Specifically, alarms were set for the following four metrics:
- ALB's
HTTPCode_Target_4XX_Count - ALB's
HTTPCode_Target_5XX_Count - ECS cluster's
MemoryUtilized - ECS cluster's
CpuUtilized
The configuration for each alarm is as follows:
Type: AWS::CloudWatch::Alarm
Properties:
AlarmName: ApplicationInsights/ApplicationInsights-ContainerInsights-ECS_CLUSTER-EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/AWS/ApplicationELB/HTTPCode_Target_4XX_Count/app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c/
AlarmDescription: This is math expression alarm created and managed by the
CloudWatch Application Insights. To make changes please go to your
application's configuration in Application Insights
Tags:
- Key: ApplicationInsightsManaged
Value: "TRUE"
ActionsEnabled: true
OKActions: []
AlarmActions: []
InsufficientDataActions: []
Dimensions: []
EvaluationPeriods: 2
DatapointsToAlarm: 2
Threshold: 0.7
ComparisonOperator: GreaterThanOrEqualToThreshold
TreatMissingData: notBreaching
Metrics:
- Id: m8
Label: HTTPCode_Target_4XX_Count
Expression: m8_HTTPCode_Target_4XX_Count/m8_RequestCount
- Id: m8_HTTPCode_Target_4XX_Count
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: AWS/ApplicationELB
MetricName: HTTPCode_Target_4XX_Count
Dimensions:
- Name: LoadBalancer
Value: app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c
Period: 300
Stat: Sum
Unit: Count
- Id: m8_RequestCount
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: AWS/ApplicationELB
MetricName: RequestCount
Dimensions:
- Name: LoadBalancer
Value: app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c
Period: 300
Stat: Sum
Unit: Count
Type: AWS::CloudWatch::Alarm
Properties:
AlarmName: ApplicationInsights/ApplicationInsights-ContainerInsights-ECS_CLUSTER-EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/AWS/ApplicationELB/HTTPCode_Target_5XX_Count/app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c/
AlarmDescription: This is math expression alarm created and managed by the
CloudWatch Application Insights. To make changes please go to your
application's configuration in Application Insights
Tags:
- Key: ApplicationInsightsManaged
Value: "TRUE"
ActionsEnabled: true
OKActions: []
AlarmActions: []
InsufficientDataActions: []
Dimensions: []
EvaluationPeriods: 2
DatapointsToAlarm: 2
Threshold: 0.1
ComparisonOperator: GreaterThanOrEqualToThreshold
TreatMissingData: notBreaching
Metrics:
- Id: m7
Label: HTTPCode_Target_5XX_Count
Expression: m7_HTTPCode_Target_5XX_Count/m7_RequestCount
- Id: m7_HTTPCode_Target_5XX_Count
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: AWS/ApplicationELB
MetricName: HTTPCode_Target_5XX_Count
Dimensions:
- Name: LoadBalancer
Value: app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c
Period: 300
Stat: Sum
Unit: Count
- Id: m7_RequestCount
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: AWS/ApplicationELB
MetricName: RequestCount
Dimensions:
- Name: LoadBalancer
Value: app/EcsNat-AlbCo-gB01lRgFgX9v/34111fdfed82112c
Period: 300
Stat: Sum
Unit: Count
Type: AWS::CloudWatch::Alarm
Properties:
AlarmName: ApplicationInsights/ApplicationInsights-ContainerInsights-ECS_CLUSTER-EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/ECS/ContainerInsights/MemoryUtilized/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/
AlarmDescription: This is math expression alarm created and managed by the
CloudWatch Application Insights. To make changes please go to your
application's configuration in Application Insights
Tags:
- Key: ApplicationInsightsManaged
Value: "TRUE"
ActionsEnabled: true
OKActions: []
AlarmActions: []
InsufficientDataActions: []
Dimensions: []
EvaluationPeriods: 2
DatapointsToAlarm: 2
Threshold: 0.9
ComparisonOperator: GreaterThanOrEqualToThreshold
TreatMissingData: ignore
Metrics:
- Id: m1
Label: MemoryUtilized
Expression: m1_MemoryUtilized/m1_MemoryReserved
- Id: m1_MemoryUtilized
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: ECS/ContainerInsights
MetricName: MemoryUtilized
Dimensions:
- Name: ClusterName
Value: EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg
Period: 300
Stat: Average
Unit: Megabytes
- Id: m1_MemoryReserved
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: ECS/ContainerInsights
MetricName: MemoryReserved
Dimensions:
- Name: ClusterName
Value: EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg
Period: 300
Stat: Average
Unit: Megabytes
Type: AWS::CloudWatch::Alarm
Properties:
AlarmName: ApplicationInsights/ApplicationInsights-ContainerInsights-ECS_CLUSTER-EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/ECS/ContainerInsights/CpuUtilized/EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg/
AlarmDescription: This is math expression alarm created and managed by the
CloudWatch Application Insights. To make changes please go to your
application's configuration in Application Insights
Tags:
- Key: ApplicationInsightsManaged
Value: "TRUE"
ActionsEnabled: true
OKActions: []
AlarmActions: []
InsufficientDataActions: []
Dimensions: []
EvaluationPeriods: 2
DatapointsToAlarm: 2
Threshold: 0.9
ComparisonOperator: GreaterThanOrEqualToThreshold
TreatMissingData: ignore
Metrics:
- Id: m3
Label: CpuUtilized
Expression: m3_CpuUtilized/m3_CpuReserved
- Id: m3_CpuUtilized
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: ECS/ContainerInsights
MetricName: CpuUtilized
Dimensions:
- Name: ClusterName
Value: EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg
Period: 300
Stat: Average
Unit: None
- Id: m3_CpuReserved
Label: input
ReturnData: false
MetricStat:
Metric:
Namespace: ECS/ContainerInsights
MetricName: CpuReserved
Dimensions:
- Name: ClusterName
Value: EcsNativeBlueGreenStack-EcsConstructCluster14AE103B-0UD5SYuupUOg
Period: 300
Stat: Average
Unit: None
For managing dashboards and alarms for each application
I checked what CloudWatch Alarms are set when configuring CloudWatch Application Insights for an ECS cluster in Container Insights.
It seems useful for managing dashboards and alarms for each application.
I hope this article helps someone.
That's all from nonPi (@non____97) in the Consulting Department of the Cloud Business Division!
