S3 what needs to ReadACL and ReadObjectTagging

Hi everyone.

I've an app that stores data in S3 via php sdk.

(1) In late April, as a security measure, I change the api of my app to create signed urls instead of just show the files using the bucket url + key of the file, and, (2) in late may, I've started using AWS Backup, that now supports S3, and created a plan to backup my bucket every day.

What happen was that the cost of S3 dramatically increased. Between January and April the GET (and all other requests EU-Requests-Tier2) were between 3,500,000 and 5,500,000. In may, after the adding of signed urls, the GET requests jumped to over 19,500,000. In June, after I started using AWS backup, the requests dropped to little over 7,000,000 but then in July the requests sky rocket to more than 120,000,000.

All over this months the usage of the app didn't change that much, in July there were more users using it but not that much different from the previous months.

In the billing of july, if I look at the details by api operation is shown that what made the price go up was the ReadACL and ReadObjectTagging operations, which leads me to ask if between AWS backup and createPresignedRequest (and getCommand('GetObject') ) what exactly is using the permission to ReadACL and ReadObjectTagging?

Thank you.