CloudWatch Logs
Definition
AWS CloudWatch Logs is a service for monitoring, storing, and accessing log files from EC2 instances and other AWS services for better insights.
Use Cases
- Netflix: Centralized troubleshooting and operational visibility for large-scale microservices running on AWS. — Netflix runs many services on AWS and relies on centralized log collection and analysis patterns. In AWS environments, teams commonly ship application and infrastructure logs from compute to a managed log service, then search and correlate logs during incidents and deployments. (Faster incident investigation and improved operational visibility by querying logs across many services and instances from a central place.)
- Expedia Group: Monitoring and troubleshooting distributed applications on AWS during peak traffic periods. — Teams aggregate logs from application components and AWS services into a centralized logging system, enabling engineers to search for errors, correlate events, and create alerts based on patterns. (Reduced mean time to detect and resolve issues by quickly finding error signatures and correlating events across services.)
Provider Equivalents
- AWS: Amazon CloudWatch Logs
- Azure: Azure Monitor Logs (Log Analytics workspace)
- GCP: Cloud Logging
- OCI: OCI Logging
Frequently Asked Questions
- What's the difference between CloudWatch Logs and CloudTrail?
- CloudWatch Logs stores and lets you search operational logs (application logs, system logs, service logs). CloudTrail records AWS API activity (who did what, when, and from where) for auditing and security. Use CloudWatch Logs for debugging and performance troubleshooting; use CloudTrail for governance, compliance, and investigating account activity.
- When should I use CloudWatch Logs?
- Use CloudWatch Logs when you need a central place to collect logs from EC2, containers, Lambda, or AWS services; search and filter logs during troubleshooting; set retention policies; and create metric filters/alarms from log patterns (for example, alert when "ERROR" spikes). It’s especially useful when you have many instances or microservices and need consistent log access without logging into servers.
- How much does CloudWatch Logs cost?
- Pricing is mainly based on how much log data you ingest (write), store, and scan/query, plus any optional features you enable. Costs increase with high-volume verbose logs, long retention periods, frequent queries/insights, and cross-account/cross-region setups. To control cost, set appropriate retention, reduce noisy log levels, and avoid scanning large time ranges unnecessarily. Exact rates vary by region and change over time, so check the CloudWatch pricing page for current numbers.
Category: monitoring
Difficulty: intermediate
Related Terms
See Also