Q: What is AWS CloudWatch?
A: AWS CloudWatch is a monitoring and observability service provided by Amazon Web Services. It allows users to collect and track metrics, collect and monitor log files, set alarms, and automatically react to changes in AWS resources.
Q: What types of data can be monitored with CloudWatch?
A: CloudWatch can monitor various types of data including metrics, log files, events, and traces.
Q: What are CloudWatch metrics?
A: CloudWatch metrics are time-ordered sets of data points that represent the behavior of your AWS resources. These metrics can be collected at intervals as short as one minute.
Q: How can I publish custom metrics to CloudWatch?
A: You can publish custom metrics to CloudWatch using the AWS SDKs or CLI. Below is an example Python code to publish a custom metric:
import boto3
cloudwatch = boto3.client('cloudwatch')
response = cloudwatch.put_metric_data(
Namespace='CustomNamespace',
MetricData=[
{
'MetricName': 'CustomMetric',
'Value': 1,
'Unit': 'Count',
'Dimensions': [
{
'Name': 'CustomDimension',
'Value': 'CustomValue'
},
]
},
]
)
Q: How can I set up CloudWatch alarms?
A: You can set up CloudWatch alarms to monitor metrics and trigger actions based on predefined thresholds. Here's an example using the AWS CLI to create an alarm:
aws cloudwatch put-metric-alarm \
--alarm-name "HighCPUUtilization" \
--alarm-description "Alarm when CPU utilization exceeds 70%" \
--actions-enabled \
--alarm-actions <ARN_of_SNS_Topic> \
--metric-name CPUUtilization \
--namespace AWS/EC2 \
--statistic Average \
--period 300 \
--threshold 70 \
--comparison-operator GreaterThanThreshold \
--dimensions Name=InstanceId,Value=<InstanceId> \
--evaluation-periods 2 \
--unit Percent
Q: Can CloudWatch be used to monitor application logs?
A: Yes, CloudWatch Logs can be used to monitor, store, and access log files from AWS resources and custom applications. You can use the AWS SDKs or CLI to publish logs to CloudWatch Logs.
Q: How can I retrieve CloudWatch metrics using the AWS SDK?
A: You can retrieve CloudWatch metrics using the AWS SDKs. Here's an example using the Boto3 Python SDK:
import boto3
cloudwatch = boto3.client('cloudwatch')
response = cloudwatch.get_metric_statistics(
Namespace='AWS/EC2',
MetricName='CPUUtilization',
Dimensions=[
{
'Name': 'InstanceId',
'Value': 'i-1234567890abcdef0'
},
],
StartTime=datetime(2024, 5, 1),
EndTime=datetime(2024, 5, 17),
Period=300,
Statistics=[
'Average',
],
Unit='Percent'
)
Important Interview Questions and Answers on AWS CloudWatch
Q: What is AWS CloudWatch?
AWS CloudWatch is a monitoring and observability service provided by Amazon Web Services. It collects and tracks metrics, logs, and events, allowing users to monitor and manage their AWS resources, applications, and services in real-time.
Q: How do you create a custom CloudWatch metric using the AWS SDK for Python (Boto3)?
Here is the code.
import boto3
# Create a CloudWatch client
cloudwatch = boto3.client('cloudwatch')
# Put custom metric data
cloudwatch.put_metric_data(
Namespace='MyNamespace',
MetricData=[
{
'MetricName': 'MyCustomMetric',
'Value': 1,
'Unit': 'Count'
}
]
)
Q: Explain the difference between CloudWatch Alarms and Events.
- CloudWatch Alarms: Alarms monitor a single metric over a specified time period and trigger actions based on predefined thresholds. For example, triggering an alarm when CPU utilization exceeds 90% for more than 5 minutes.
- CloudWatch Events: Events respond to changes in AWS resources or application state. They can be used to trigger automated actions based on events such as instance state changes, S3 object creation, or CloudTrail API activity.
Q: How can you create a CloudWatch Alarm using AWS CloudFormation?
Here is the code.
Resources:
MyAlarm:
Type: AWS::CloudWatch::Alarm
Properties:
AlarmDescription: "Alarm for high CPU utilization"
Namespace: "AWS/EC2"
MetricName: "CPUUtilization"
Dimensions:
- Name: "InstanceId"
Value: "i-1234567890abcdef0"
Statistic: Average
Period: 300
EvaluationPeriods: 1
Threshold: 90
ComparisonOperator: GreaterThanThreshold
AlarmActions:
- "arn:aws:sns:us-east-1:123456789012:MyTopic"
Q: How do you retrieve and display CloudWatch Logs using the AWS CLI?
Here is the code.
aws logs get-log-events --log-group-name MyLogGroup --log-stream-name MyLogStream
Q: Explain the concept of CloudWatch Logs Insights.
CloudWatch Logs Insights is a feature that enables you to search and analyze log data in CloudWatch Logs. It allows you to query your log data using a purpose-built query language and provides visualizations to help you understand patterns, trends, and anomalies in your log data.
Q: How can you create a CloudWatch Dashboard using the AWS Management Console?
- Go to the CloudWatch console.
- In the navigation pane, choose "Dashboards", then "Create dashboard".
- Enter a name for your dashboard, then choose "Create dashboard".
- Choose "Add widget" to add metrics, logs, or text to your dashboard.
- Configure the widget settings and choose "Create widget".
