Tutorial / Cram Notes
Monitoring applications and infrastructure is a crucial task for DevOps engineers to ensure that systems are running optimally and to quickly identify and address any issues that arise. AWS provides a variety of tools that can help you monitor your applications and infrastructure effectively.
AWS CloudWatch
Amazon CloudWatch is a monitoring service for AWS cloud resources and the applications you run on AWS. It provides you with data and actionable insights to monitor your applications, understand and respond to system-wide performance changes, optimize resource utilization, and get a unified view of operational health.
Key Features:
- Metrics: Collect and track key metrics, collect log files, and set alarms.
- Logs: Collect, monitor, analyze, and store log files from your infrastructure, AWS services, and on-premises servers.
- Events: Respond to state changes in your AWS resources.
- Alarms: Automate notifications or take actions based on predefined rules.
Amazon CloudWatch Examples:
To monitor EC2 instance CPU Utilization:
aws cloudwatch get-metric-statistics –namespace AWS/EC2 –metric-name CPUUtilization –dimensions Name=InstanceId,Value=i-1234567890abcdef0 –statistics Average –start-time 2021-01-01T23:18:00 –end-time 2021-01-02T23:18:00 –period 300
To create a CloudWatch alarm for CPU utilization:
aws cloudwatch put-metric-alarm –alarm-name “High CPU Utilization” –metric-name CPUUtilization –namespace AWS/EC2 –statistic Average –period 300 –threshold 80 –comparison-operator GreaterThanOrEqualToThreshold –dimensions Name=InstanceId,Value=i-1234567890abcdef0 –evaluation-periods 2 –alarm-actions arn:aws:sns:us-west-2:111122223333:MyTopic
AWS CloudTrail
AWS CloudTrail is a service that enables governance, compliance, operational auditing, and risk auditing of your AWS account. With CloudTrail, you can log, continuously monitor, and retain account activity related to actions across your AWS infrastructure. CloudTrail provides event history of your AWS account activity, including actions taken through the AWS Management Console, AWS SDKs, command line tools, and other AWS services.
Key Features:
- Log Files: Deliver an event log for actions taken within your account.
- Event History: View, search, and download recent AWS account activity.
- Integrations: Integrate with Amazon CloudWatch Logs for real-time analysis and indexing.
AWS X-Ray
AWS X-Ray helps developers analyze and debug production, distributed applications, such as those built using a microservices architecture. X-Ray provides an end-to-end view of requests as they travel through your application and shows a map of your application’s underlying components.
Key Features:
- Request Tracing: Trace requests as they travel through your applications.
- Service Map: Visualize and identify issues within your application topology.
- Analytics: Analyze application performance and pinpoint root causes of issues.
AWS X-Ray Example:
To get started with tracing HTTP requests:
AWSXRayRecorder recorder = AWSXRayRecorderBuilder.defaultRecorder();
Segment segment = recorder.beginSegment(“MyApp”);
// Perform some work
doSomeWork();
// Before your application returns its response or throws an exception
recorder.endSegment();
AWS Config
AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources. Config continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired configurations.
Key Features:
- Configuration History: View detailed configuration histories of your AWS resources.
- Config Rules: Automated compliance checks based on AWS best practices.
- Resource Relationships: View relationships between resources, even across regions and accounts.
Comparison Table for Monitoring Services
| Service | Use Case | Features |
|---|---|---|
| CloudWatch | Real-time monitoring of AWS resources and applications | Metrics, Logs, Events, Alarms |
| CloudTrail | Governance, compliance, and auditing of AWS accounts | Log files, Event history, Activity monitoring |
| X-Ray | Analysis and debugging of distributed applications | Request tracing, Service map, Analytics |
| Config | Configuration management and compliance auditing of AWS resources | Configuration history, Config rules, Resource relationships |
AWS provides these and other tools like Amazon Inspector, Elastic Load Balancing (ELB) Access Logs, and AWS Lambda function logging to help you comprehensively monitor your applications and infrastructure. Each of these services is designed to address different aspects of monitoring and can be combined to provide a robust monitoring solution tailored to meet the specific needs of your environment. As you prepare for the AWS Certified DevOps Engineer – Professional (DOP-C02) exam, familiarizing yourself with these services and their capabilities is essential for designing, deploying, and managing the monitoring solutions in AWS.
Practice Test with Explanation
True/False: AWS CloudWatch can be used to monitor both AWS resources and on-premises servers.
- Answer: True
Explanation: AWS CloudWatch can monitor AWS resources such as EC2 instances, DynamoDB tables, and RDS DB instances, as well as your on-premises servers, providing a unified view of AWS and non-AWS resources.
True/False: AWS X-Ray is a service used to debug and trace microservices.
- Answer: True
Explanation: AWS X-Ray helps developers analyze and debug distributed applications, such as those built using a microservices architecture, by providing insights into how the applications and its underlying services are performing.
Multiple Select: Which of the following metrics are provided by AWS CloudWatch by default? (Choose two)
- a) CPU Utilization
- b) Memory Utilization
- c) Network Utilization
- d) Disk Read Ops
Answer: a) CPU Utilization, c) Network Utilization
Explanation: AWS CloudWatch automatically provides metrics such as CPU Utilization and Network Utilization for AWS services. However, Memory Utilization and Disk Read Ops are custom metrics that need to be monitored using custom scripts.
Multiple Select: Which AWS services are typically used for log storage and analysis? (Choose two)
- a) AWS CloudTrail
- b) Amazon CloudWatch Logs
- c) AWS X-Ray
- d) AWS Config
Answer: a) AWS CloudTrail, b) Amazon CloudWatch Logs
Explanation: AWS CloudTrail is used for auditing API calls and related events in AWS, and Amazon CloudWatch Logs are used to store and analyze log data.
True/False: It is not possible to set alarms in AWS CloudWatch based on custom log data.
- Answer: False
Explanation: In AWS CloudWatch, you can set alarms based on any log data, including custom log data. This allows you to be automatically notified when certain events or conditions are detected in your log data.
Single Select: What service would you use to collect infrastructure logs for long term analysis?
- a) Amazon S3
- b) Amazon CloudWatch
- c) Amazon Kinesis
- d) AWS Glue
Answer: a) Amazon S3
Explanation: Amazon S3 can be used to store logs for long-term retention and analysis. While CloudWatch provides real-time monitoring, it’s not optimized for long-term storage of log data.
True/False: Amazon Inspector can be used to run security vulnerability assessments on your AWS infrastructure.
- Answer: True
Explanation: Amazon Inspector is an automated security assessment service that helps improve the security and compliance of applications deployed on AWS.
True/False: AWS CloudWatch can natively monitor the memory utilization of an EC2 instance without installing additional scripts or agents.
- Answer: False
Explanation: AWS CloudWatch does not natively support memory utilization monitoring for EC2 instances. You need to install custom CloudWatch agents or scripts to push this metric to CloudWatch.
True/False: AWS Lambda functions automatically provide detailed execution logs via AWS CloudWatch Logs.
- Answer: True
Explanation: AWS Lambda automatically streams logs to AWS CloudWatch Logs where you can view metrics such as invocation count, duration, and error rates.
Single Select: What AWS service provides a detailed billing report that can be used for cost analysis?
- a) AWS Cost Explorer
- b) AWS Budgets
- c) Amazon QuickSight
- d) AWS CloudTrail
Answer: a) AWS Cost Explorer
Explanation: AWS Cost Explorer is a service that enables you to visualize, understand, and manage your AWS costs and usage over time.
True/False: AWS Systems Manager provides a capability to view operational data from multiple AWS services and automate operational tasks across your AWS resources.
- Answer: True
Explanation: AWS Systems Manager gives you visibility and control of your AWS infrastructure. It provides a unified user interface that allows you to view operational data from multiple AWS services and automate operational tasks.
Single Select: Which tool can be used to automate compliance checks and enforce your AWS resource configurations to adhere to your organization’s policies?
- a) AWS Config
- b) Amazon Inspector
- c) AWS Service Catalog
- d) AWS Trusted Advisor
Answer: a) AWS Config
Explanation: AWS Config continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired configurations.
Interview Questions
What AWS service would you use to collect and track metrics for your applications and infrastructure?
AWS CloudWatch is the service used to collect and track metrics, log files, set alarms, and automatically react to changes in AWS resources. CloudWatch can monitor AWS resources such as EC2 instances, DynamoDB tables, and RDS DB instances, as well as custom metrics generated by your applications and services.
How can you monitor and get notified when there is an unusual spike in your application load?
By setting up CloudWatch alarms, which react to changes in your environment. These alarms can send notifications through Amazon Simple Notification Service (SNS) when specific thresholds are breached. Metrics such as CPU usage, network traffic, or request count can be monitored for anomalies.
Can you explain how AWS X-Ray helps with monitoring applications?
AWS X-Ray helps developers analyze and debug production, distributed applications, such as those built using a microservices architecture. X-Ray provides insights into how your application and its underlying services are performing to identify and troubleshoot the root cause of performance issues and errors.
How would you monitor the health of your EC2 instances in an Auto Scaling group?
We can use EC2 instance status checks and CloudWatch metrics to monitor instance health within an Auto Scaling group. Additionally, Elastic Load Balancing (ELB) health checks can be employed to monitor instances’ health, which tie into Auto Scaling policies to replace unhealthy instances automatically.
How can you automatically remediate infrastructure issues detected by CloudWatch Alarms?
By creating CloudWatch Alarms that trigger automated actions using AWS Systems Manager Automation, AWS Lambda functions, or Auto Scaling policies. These actions can perform various remediation tasks like restarting EC2 instances, adjusting thresholds, or escalating issues to on-call personnel.
Explain how using Amazon CloudWatch Logs Insights would help with monitoring your log files?
Amazon CloudWatch Logs Insights enables you to interactively search and analyze your log data in CloudWatch Logs. You can perform queries to help you better understand your log data, identify trends, pinpoint operational issues, and take action to remedy them.
Describe the role of AWS CloudTrail in monitoring AWS infrastructure.
AWS CloudTrail is a service that provides governance, compliance, operational auditing, and risk auditing of your AWS account. It enables you to log, continuously monitor, and retain account activity related to actions across your AWS infrastructure, thereby providing a history of AWS API calls for your account.
How do you ensure that you’re monitoring all aspects of your application stack in AWS?
By utilizing a variety of AWS monitoring tools such as AWS CloudWatch for metrics and logs, AWS X-Ray for application analysis, AWS CloudTrail for API call tracking, and additional third-party tools or AWS partner solutions that integrate with AWS for comprehensive monitoring capabilities.
What are CloudWatch Agent and its benefits for monitoring?
The CloudWatch Agent is a software module that can be installed on your servers to send both system-level metrics and log files to CloudWatch. It allows you to collect more system-level metrics than those provided by default in CloudWatch, such as memory utilization and disk swap usage, and allows you to collect logs from the servers as well.
How would you use tags to simplify monitoring large numbers of AWS resources?
By applying tags to AWS resources, you can filter and aggregate metrics and logs based on these tags in CloudWatch. This simplifies monitoring by allowing you to quickly identify and organize resources by application, environment, team, or any other dimensions relevant to your business.
Explain how you can monitor the flow of data between services in AWS.
Using AWS X-Ray, you can trace and visualize the data as it moves through the various components of your application hosted in AWS. This helps in understanding dependencies, identifying bottlenecks, and pinpointing the source of issues.
How can you set up alarms in AWS for billing thresholds?
You can use AWS Budgets to define the maximum amount you want to spend on your AWS services. Then, you create CloudWatch Alarms based on the predicted or actual charges associated with your AWS account by sending notifications when your costs exceed the thresholds you set.
This blog post is really helpful for AWS Certified DevOps Engineer – Professional exam preparation. Thanks!
Can anyone suggest the best practices for setting CloudWatch alarms?
What’s the advantage of using AWS X-Ray for monitoring applications?
Great article! it cleared many doubts I had about monitoring infrastructure with AWS.
I found the walkthrough on creating CloudFormation stacks particularly useful. Thanks!
Is it necessary to use AWS Trusted Advisor for monitoring purposes?
Not convinced about the necessity of integrating AWS CloudTrail for simple applications. Any thoughts?
Thanks for this detailed guide on monitoring. It’s very insightful!