What is AWS CloudWatch?

AWS CloudWatch is a monitoring service designed to collect and track metrics about resources and applications run on AWS. CloudWatch ensures visibility into system performance and even has alerting features that can notify users of issues. It offers both basic (free) and detailed (paid) monitoring, depending on the AWS service.

AWS CloudWatch Key Features

CloudWatch’s key features include dashboards, metric collection, log monitoring, and alarms. All of these are built around a set of monitoring systems which look at different components of the AWS ecosystem.

1. Metrics collection and tracking

• Monitors metrics such as CPU usage, memory utilization, disk I/O, and network activity across AWS resources like EC2, RDS, and Lambda.
• Metrics are typically stored in an Amazon EC2 bucket and serve as a metrics repository.

2. Monitoring systems

• A variety of monitoring systems, such as application, network, and infrastructure monitoring.
• Application monitoring focuses on application health, such as latency, availability, and faults.
• Network Monitoring has Internet Monitor and Network Monitor to track both global (Internet) traffic and hybrid (on-prem with cloud) latency and packet loss.
• Infrastructure monitoring can include insights into your containers (Amazon Elastic and Kubernetes) for resource usage such as CPU, memory, and so on. It can also track your AWS Lambda applications for the same metrics.

3. Real-time dashboards

• Provides customizable dashboards for visualizing system performance and trends in real time.
• Can showcase custom applications and metrics of choice

CloudWatch Dashboard: Amazon Documentation

4. Alarms and thresholds

• Sets alarms to detect and respond to anomalies in performance, automatically triggering actions or sending alerts.
• Some actions, including launching more instances or stopping under-used instances.

AWS CloudWatch Use Cases

Let’s look at a few specific use cases for AWS CloudWatch.

Performance optimization

AWS CloudWatch helps identify bottlenecks and optimize resource usage. For instance, Internet Monitor can detect latency issues on a global cloud gaming platform and recommend deploying servers in more optimal regions to reduce lag.

Automated alert

Set up alarms based on predefined thresholds for resource scaling or error detection. For example, when Service Level Objectives (SLOs) for an application are not met, CloudWatch can send alerts and offer actionable recommendations to enhance performance metrics.

Continuous visibility

Use dashboards to maintain real-time insights into system health. Dashboards are particularly useful for tracking the performance of data streams from services like AWS Kinesis and AWS Lambda. A great way to understand this process is this course on Streaming Data with AWS Kinesis and Lambda which has you ultimately build dashboards with AWS CloudWatch.

What is AWS CloudTrail?

AWS CloudTrail is a logging service designed to track all API activity in your AWS account, ensuring accountability. It records user actions, resource changes, and service interactions, providing an immutable audit trail for governance and compliance purposes. This is particularly useful for security compliance and auditing user behavior. If you want to learn more, check out this course on AWS Security and Cost Management.

AWS CloudTrail Key Features

The key CloudTrail features revolve around monitoring user activity. Since the goal of CloudTrail is to maintain accountability and auditing ability, it makes sense that all actions will be monitored and stored.

1. Action tracking

CloudTrail logs all user actions, and this comprehensive tracking is critical for understanding the "who, what, and when" of your AWS environment.

2. Compliance support

Helps organizations meet regulatory requirements like PCI DSS and HIPAA by maintaining event history records.

In the event of violations, it can be used to track the exact timing and user account involved in the violation.

4. Integration with AWS services

CloudTrail can send logs to S3 for long-term storage or to Amazon Athena for querying and analysis. These integrations make it easier to analyze trends or investigate anomalies.

Example of CloudTrail Logs: AWS CloudTrail Blog

AWS CloudTrail Use Cases

There are a few key use cases for AWS CloudTrail that circle around audits and compliance tracking.

Security audits

CloudTrail enables detailed auditing to ensure compliance with regulatory standards and internal policies. In the event of a security incident, CloudTrail logs provide the details needed to identify the root cause and assess the impact.

CloudTrail Audit Logs: AWS Security Maturity Model

Change troubleshooting

By reviewing logs, teams can trace changes to resources that might have caused unexpected behavior. This allows for a more straightforward way to solve any future downstream issues.

CloudTrail vs. CloudWatch: Key Differences

As stated previously, both CloudTrail and CloudWatch are fundamental logging tools in the AWS environment. However, both of these look at different components of the AWS environment and this section will cover those key differences from focus to cost.

Focus

CloudWatch and CloudTrail focus on different parts of the AWS environment.

• CloudWatch: Monitors resource performance and operational health. The goal here is to understand how AWS components are running and whether or not there are issues with latency, customer interaction, or resource limitations.
• CloudTrail: Tracks API activity for governance and compliance. The goal here is to maintain a clear “paper trail” for accountability.

Data Latency

CloudWatch has nearly zero latency, whereas CloudTrail has some latency.

• CloudWatch: Provides near real-time insights, with metrics updated as frequently as every minute. It is critical to have real-time insights as CloudWatch needs to be able to provide instantaneous alerting or make changes to resources as needed.
• CloudTrail: Logs API activity with a delay of a few minutes, focusing on historical analysis. Since the logs are generally used to look at historical actions, a lag of a few minutes is acceptable.

Integration

Both integrate seamlessly with AWS services like Lambda, S3, and SNS.

• CloudWatch: Best for operational monitoring and automated responses to performance metrics. It can also integrate with containers like Kubernetes, EC2 storage, and other applications for more detailed logging for particular use cases.
• CloudTrail: Ideal for security auditing and tracking user activities. It will integrate with EC2 storage for logging storage.

Cost

Both have a cost-free basic logging but offer advanced logging at a cost.

• CloudWatch: Basic logging of resource usage, faults, and issues is generally free. More detailed logging has costs based on the volume of metrics collected, alarms set, and complexity of data stored. Different applications have varying levels of logging detail.
• CloudTrail: Management event logging is free, but logging data events and advanced analysis incurs additional charges.

Logging Data

How logs are collected and stored differs between the two tools based on their unique use cases.

• CloudWatch: Data is provided in real-time, but can be aggregated based on timeframes. Since exact detail may not be necessary, the data provided is generally summarized at the timescale it was collected.
• CloudTrail: With the goal of providing accurate and detailed audit trails, it does not aggregate activity. Instead, it provides information on every action that was taken to create a clear outline of actions.

Key Difference Summary

Here is a table summarizing the key differences.

CloudTrail vs. CloudWatch vs. AWS Config

While CloudTrail and CloudWatch handle logging and monitoring, AWS Config focuses on tracking configuration changes to AWS resources. This makes it useful for understanding how the current configuration is impacting your AWS resources. AWS Config itself is not a logging tool, but rather helps you understand how changes have impacted your AWS resource management.

• CloudTrail: Logs API activity for security and auditing to meet compliance standards
• CloudWatch: Monitors the performance of AWS resources and can be used for alarms 
• AWS Config: Ensures configuration changes stay within bounds and can showcase how changes impacted resources.

Conclusion: When to Use CloudTrail and CloudWatch

For AWS users, the choice between CloudTrail and CloudWatch boils down to their goal. Use CloudWatch if you need to monitor system performance, track operational metrics, and automate responses to anomalies. Use CloudTrail if your focus is on security, compliance, or auditing user activities. 

Understanding which tool to use is critical for comprehensive monitoring, logging, and maintaining AWS infrastructure. If you want to learn more about AWS and how these tools work, check out some resources:

• How to Set Up and Configure AWS
• AWS Certifications
• AWS Cloud Technology and Services