Cloudwatch

Cloudwatch Metrics

• Cloudwatch provide metrics for every AWS Service
• Metrics is a variable to monitor, such as
• CPU Utilization
• Networking data
• Metric belong to Namespace
• Namespace are similar to Group
• Metric dimensions are Attribute, like
• Instance ID
• Environment Name
• Each Metric can have up to 10 Dimensions
• Metrics have Timestamps
• Using metric, the Cloudwatch Dashboard is generated

Cloudwatch Detailed Monitoring

• By default, EC2 have metrics each 5 minutes
• With Detailed Monitoring
• Metric generate every 1 Minute
• Good for ASG
• Free Tier allows 10 Detail Monitoring
• For EC2 Memory Usage, there is no default metric. Need to use Custom Metric

Cloudwatch Custom Metric

• Can send custom metrics to Cloudwatch
• Ability to send Dimension
• instance.id
• environment.name
• Metric Resolution
• Standard 1 Minute
• High Resolution, up to 1 Sec
• To send custom metric use PutMetricData

Cloudwatch Dashboard

• Dashboard are Global (cross region, cross account)
• Dashboard Graph includes different Region
• Dashboard Graph includes different Account
• Can setup Auto Refresh
• Pricing
• 3 Dashboard (Up to 50 Metrics) free
• After free tier, 3 dollar/dashboard/per month

Cloudwatch Logs

• Logs can be send to Cloudwatch through SDK
• Cloudwatch collect log from
• Elastic Beanstalk
• ECS
• AWS Lambda
• VPC Flow Logs
• API Gateway
• Cloudtrail
• Cloudwatch Log Agent (From EC2 Instance)
• Route 53 (DNS Query)
• Logs go to
• S3 to store or archive
• Stream to Elastic Search for analytics
• Log Storage Architecture
• Groups: Log is grouped under name
• Each group has streams of logs
• Can define expiration period (After the expiration period, the logs will be deleted)
• Encryption
• KMS can be used to encrypt the logs
• Encryption is done in log group level
• Using encryption key, both new (create-log-group) and existing (associate) log group can be encrypted
• Encryption operation can be done only by CLI or SDK
• To send logs, make sure the Permission to write logs are set
• To follow/tail logs, we can use AWS CLI
• Possible to filter by expression
• Helpful to find logs or specific IP
• Can use to trigger alarm
• Cloudwatch Logs Insights
• Can be used to query logs
• To use, need to install the Unified Cloudwatch Logs Event

Cloudwatch Logs Agent Vs Unified Agent

Logs Agent

• Old Version

Unified Agent

• Newer version
• Get Additional system level metrics
• Can use SSM Parameter Store to centralized configuration

Cloudwatch Alarms

• Alarms are used to trigger notification for any metric
• Alarms can go to
• ASG
• EC2 Actions
• SNS Notifications
• Alarm can raise
• Sampling value
• Percentage value
• Max or Min value
• Alarm States
• OK (When everything is alright)
• INSUFFICIENT_DATA (When not enough data to measure it its OK or ALARM state)
• ALARM (When metrics reached the Threshold)
• Period
• Time length to evaluate the metric
• In case of High Resolution Metric, period can be 10 sec

Creating Cloudwatch Event

While creating a cloudwatch event, we can set

1. Period: Define evaluation time in seconds.
2. Evaluation Period / Number of Data Point: Known as Data Point. Number of recent Period to consider to generate a alarm state
3. DataPoints To Alarm: Determine to go to ALARM state. We can define how many period can be reached within a evaluation period to go to ALARM

Cloudwatch Event

• Can schedule CRON Jobs
• Event Pattern
• Rules on react a service doing something
• Example: Code Pipeline state change
• Can trigger
• Lambda Function
• SQS
• SNS
• Kinesis
• Cloudwatch Event create a sample document to give information about the change
• Use case in S3 and Code Pipeline
• Code can be uploaded to S3
• Cloudwatch Event trigger the Code Pipeline
• Code will be deployed to the Elastic Beanstalk
• Can be used to change the number of Fargate Cluster should run according to the events
• Allow monitor jobs in the batch jobs

Cloudwatch Agent

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• Collect system info and log files
• Can track memory, swap and disk space