ORCA Decommission: Research Ticket

[krisstanton]

Ticket to hold any pre-research needed on this task.

The overall goal here is to check and see what is required to remove ORCA from Cumulus after setting up versioning.
This ticket may be on-going throughout the process of setting up the S3 versioning and untangling ORCA from Cumulus.

Documentation:
https://nasa.github.io/cumulus/docs
https://nasa.github.io/cumulus-orca/

Also read through the official slack channels to see if there are any other special instructions or things to consider.

[krisstanton]

Here is a good doc source for info on S3 Versioning and workflows.
https://docs.aws.amazon.com/AmazonS3/latest/userguide/versioning-workflows.html

At this time, I believe it is safe to switch on bucket versioning to Sandbox and UAT.
With bucket versioning, each object now gets assigned an ID that is used to retrieve previous versions of the object.
Deleting an object does not actually delete it, just assigns a delete marker.
To actually permanently delete an object, you have to specify the object and it's ID. In that case no delete marker will be set and the object will be permanently deleted.

[krisstanton]

It looks as though there should not be any problems with current files when enabling versioning on any of the buckets.
After enabling versioning on Sandbox and UAT, I also experimented with running tests, overwriting files, deleting and restoring files.
See this comment for details: #490 (comment)

[emmalu]

This work has been de-prioritizing for the time being. Let's keep all of the tickets open, let's just move out of this PI.