Introduction to Amazon CloudWatch Logs
Amazon CloudWatch Logs is a scalable service designed to monitor, store, and access log files from Amazon Elastic Compute Cloud (Amazon EC2) instances, AWS CloudTrail, Route 53, and other sources. It centralizes logs from all systems, applications, and AWS services, providing a unified view for analysis. Users can efficiently view, search for specific error codes or patterns, filter logs based on fields, and archive data securely.
The service facilitates a consistent flow of events ordered by time, enabling powerful querying, sorting by dimensions, grouping by fields, and custom computations. CloudWatch Logs also supports visualizing log data in dashboards.
Key Features
- Query Log Data: Utilize CloudWatch Logs Insights for interactive searching and analysis with a purpose-built query language.
- Monitor EC2 Instances: Track application and system logs, monitor error rates, and receive notifications when thresholds are exceeded. Log data is encrypted in transit and at rest.
- Monitor AWS CloudTrail Events: Create alarms and receive notifications for specific API activities captured by CloudTrail for troubleshooting.
- Log Retention: Configure retention policies for log groups, with options for indefinite retention or periods between one day and ten years.
- Archive Log Data: Store log data in highly durable storage, easily sending rotated and non-rotated log data off-host for future access.
- Log Route 53 DNS Queries: Capture information about DNS queries received by Route 53.
Related AWS Services
Amazon CloudWatch Logs integrates with several other AWS services:
- AWS CloudTrail: Monitors API calls made to your account, capturing logs and delivering them to an Amazon S3 bucket.
- AWS Identity and Access Management (IAM): Provides secure control over access to AWS resources for users.
- Amazon Kinesis Data Streams: Enables rapid and continuous data intake and aggregation for various data types, including logs.
- AWS Lambda: Allows the creation of applications that respond to new information by running code as Lambda functions on highly available compute infrastructure.
Getting Started
To use Amazon CloudWatch Logs, an AWS account is required. Users can sign up for an AWS account and then access the CloudWatch console via a web-based interface or configure the AWS Command Line Interface (AWS CLI) for operations.
AWS offers two primary options for collecting logs:
- Unified CloudWatch Agent (Recommended): Collects both logs and advanced metrics with a single agent, supporting multiple operating systems and offering better performance.
- Previous CloudWatch Logs Agent: Supports log collection from Linux servers. While still functional, it is recommended to migrate to the unified agent due to deprecation of required Python versions.
For detailed instructions on installation and configuration, refer to the respective sections within the user guide.
Pricing
New AWS users can utilize CloudWatch Logs for free through the AWS Free Tier. Standard rates apply for logs stored by other services that use CloudWatch Logs, such as Amazon VPC flow logs and Lambda logs. For detailed pricing information, please refer to Amazon CloudWatch Pricing.
Core Concepts
- Log Events: Records of activity containing a timestamp and the raw event message (UTF-8 encoded).
- Log Streams: Sequences of log events from the same source, typically representing events from a single application instance or resource.
- Log Groups: Collections of log streams that share common retention, monitoring, and access control settings.
- Metric Filters: Extract metric observations from ingested events and transform them into data points for CloudWatch metrics.
- Retention Settings: Define how long log events are kept, with automatic deletion of expired events.
