Publish flow logs to CloudWatch Logs - Amazon Virtual Private Cloud
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Publish flow logs to CloudWatch Logs

Flow logs can publish flow log data directly to Amazon CloudWatch. Amazon CloudWatch is a comprehensive monitoring and observability service. It collects and tracks metrics, logs, and event data from various Amazon resources, as well as your own applications and services. CloudWatch provides visibility into resource utilization, application performance, and operational health, enabling you to detect and respond to system-wide performance changes and potential issues. With CloudWatch, you can set alarms, visualize logs and metrics, and automatically react to collect and optimize your cloud resources. It is an essential tool for ensuring the reliability, availability, and performance of your cloud-based infrastructure and applications.

When publishing to CloudWatch Logs, flow log data is published to a log group, and each network interface has a unique log stream in the log group. Log streams contain flow log records. You can create multiple flow logs that publish data to the same log group. If the same network interface is present in one or more flow logs in the same log group, it has one combined log stream. If you've specified that one flow log should capture rejected traffic, and the other flow log should capture accepted traffic, then the combined log stream captures all traffic.

In CloudWatch Logs, the timestamp field corresponds to the start time that's captured in the flow log record. The ingestionTime field indicates the date and time when the flow log record was received by CloudWatch Logs. This timestamp is later than the end time that's captured in the flow log record.

For more information about CloudWatch Logs, see Logs sent to CloudWatch Logs in the Amazon CloudWatch Logs User Guide.

Pricing

Data ingestion and archival charges for vended logs apply when you publish flow logs to CloudWatch Logs. For more information, open Amazon CloudWatch Pricing, select Logs and find Vended Logs.