Finding your CloudTrail log files - Amazon CloudTrail
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Finding your CloudTrail log files

CloudTrail publishes log files to your S3 bucket in a gzip archive. In the S3 bucket, the log file has a formatted name that includes the following elements:

  • The bucket name that you specified when you created trail (found on the Trails page of the CloudTrail console)

  • The (optional) prefix you specified when you created your trail

  • The string "AWSLogs"

  • The account number

  • The string "CloudTrail"

  • A Region identifier such as us-west-1

  • The year the log file was published in YYYY format

  • The month the log file was published in MM format

  • The day the log file was published in DD format

  • An alphanumeric string that disambiguates the file from others that cover the same time period

The following example shows a complete log file object name:

bucket_name/prefix_name/AWSLogs/Account ID/CloudTrail/region/YYYY/MM/DD/file_name.json.gz

For organization trails, the log file object name includes the organization unit ID in the path, as follows:

bucket_name/prefix_name/AWSLogs/O-ID/Account ID/CloudTrail/Region/YYYY/MM/DD/file_name.json.gz

To retrieve a log file, you can use the Amazon S3 console, the Amazon S3 command line interface (CLI), or the API.

To find your log files with the Amazon S3 console
  1. Open the Amazon S3 console.

  2. Choose the bucket you specified.

  3. Navigate through the object hierarchy until you find the log file you want.

    All log files have a .gz extension.

You will navigate through an object hierarchy that is similar to the following example, but with a different bucket name, account ID, Region, and date.

All Buckets Bucket_Name AWSLogs 123456789012 CloudTrail us-west-1 2014 06 20

A log file for the preceding object hierarchy will look like the following:


Although uncommon, you may receive log files that contain one or more duplicate events. In most cases, duplicate events will have the same eventID. For more information about the eventID field, see CloudTrail record contents.