Send logs to CloudWatch Logs - Amazon CloudWatch

Send logs to CloudWatch Logs

To send logs from your containers to Amazon CloudWatch Logs, you can use Fluent Bit or Fluentd. For more information, see Fluent Bit and Fluentd.

If you are not already using Fluentd, we recommend that you use Fluent Bit for the following reasons:

  • Fluent Bit has a smaller resource footprint and is more resource-efficient with memory and CPU usage than Fluentd. For a more detailed comparison, see Fluent Bit and Fluentd performance comparison.

  • The Fluent Bit image is developed and maintained by AWS. This gives AWS the ability to adopt new Fluent Bit image features and respond to issues much quicker.

Fluent Bit and Fluentd performance comparison

The following tables show the performance advantage that Fluent Bit has over Fluentd in memory and CPU usages. The following numbers are just for reference and might change depending on the environment.

Logs per second Fluentd CPU usage Fluent Bit CPU usage with Fluentd-compatible configuration Fluent Bit CPU usage with optimized configuration

100

0.35 vCPU

0.02 vCPU

0.02 vCPU

1,000

0.32 vCPU

0.14 vCPU

0.11 vCPU

5,000

0.85 vCPU

0.48 vCPU

0.30 vCPU

10,000

0.94 vCPU

0.60 vCPU

0.39 vCPU

Logs per second Fluentd memory usage Fluent Bit memory usage with Fluentd-compatible configuration Fluent Bit memory usage with optimized configuration

100

153 MB

46 MB

37 MB

1,000

270 MB

45 MB

40 MB

5,000

320 MB

55 MB

45 MB

10,000

375 MB

92 MB

75 MB