Amazon S3 file format (http://docs.aws.amazon.com/AmazonS3/latest/dev/LogFormat.html) includes a few additional fields that are currently ignored by log importer.
Example S3 log line:
xyzxyz hello.mobile [15/May/2015:00:52:49 +0000] 18.104.22.168 arn:aws:iam::179580289999:user/phillip.boss 82303D395D REST.GET.VERSIONING - "GET /?versioning HTTP/1.1" 200 - 162 - 9 - "-" "aws-sdk-java/1.9.8 Linux/3.9.5-301.fc19.x86_64 Java_HotSpot(TM)_64-Bit_Server_VM/20.13-b02/1.6.0_38-ea" -
arn:aws:iam::179580289999:user/phillip.boss, is the
Requester field which contains some interesting information:
The canonical user ID of the requester, or the string "Anonymous" for unauthenticated requests. If the requester was an IAM user, this field will return the requester's IAM user name along with the AWS root account that the IAM user belongs to. This identifier is the same one used for access control purposes.
Moved to the right issue tracker in https://github.com/piwik/piwik-log-analytics/issues/86