DynamoDB TTL

[Dnomyar]

Short description

Add feature to allow to expire DynamoDB items.

Details

DynamoDB has the feature that allow to expire an item based on a field value. In a nutshell, if the today > than the date specified in the item, the item is eventually going to get delete by DynamoDB. It is useful to handle the data retention.

I suggest having a configuration at the table level. It would contain:

• the field name that need to be specified when the dynamo TTL feature is turned on.
• the ttl that would specify the delay for the item to be deleted.

my-dynamodb-journal { // also available for snapshots tables
  dynamodb-item-ttl-config {
    field-name = "expiresAt" // in the AWS UI, we need to set the field name https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/time-to-live-ttl-how-to.html
    ttl = 30d
  }
}

Then, for each insertion in the journal and snapshot, a new field would be added: expiresAt -> now + 30d.
This configuration is optional. The field would only be added if the field-name and ttl are defined.

What do you think about this approach?

I also have a suggestion of implementation #99