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Compute logs not visible in Dagster+ UI — "No Log File Available" error

Problem description​

AWS hybrid agents successfully capture compute logs in S3 buckets, but the logs are not visible in the Dagster+ UI. Users see the message "No Log File Available" even though logs are being written to S3 correctly.

Symptoms​

  • Message "No Log File Available" appears in the UI.
  • Both stdout and stderr tabs appear empty.
  • Log links at the bottom start with /tmp/ instead of s3:/.
  • Logs are successfully written to S3 bucket but not displayed in the UI.

Root cause​

The compute log manager is not configured correctly in the deployment configuration. Specifically, the configuration key uses computeLogs instead of the correct compute_logs format.

Solution​

Change computeLogs to compute_logs in your deployment configuration.

Step-by-step resolution​

  1. Locate your deployment configuration (typically in Helm chart values).

  2. Update the configuration key from computeLogs to compute_logs:

    compute_logs: # <- here
      enabled: true
      custom:
        module: dagster_aws.s3.compute_log_manager
        class: S3ComputeLogManager
        config:
          show_url_only: false
          bucket: your-s3-bucket-name
          region: us-east-1
          prefix: 'your-deployment-name'
          use_ssl: true
          verify: true
          verify_cert_path: '/etc/ssl/certs/ca-certificates.crt'

  3. Deploy the updated configuration.

  4. Verify that new runs show logs in both stdout and stderr tabs.

  5. Check that log links now start with s3:/ instead of /tmp/.

Alternative solutions​

Ensure your S3 bucket is in the same region as your Dagster+ organization and verify IAM permissions allow Dagster+ to read from S3.

Prevention​

Always use the correct configuration key format compute_logs when setting up S3 compute log managers. Double-check your deployment configuration against the official documentation before deploying.