Which recommendation would resolve this issue?
Ensure the DynamoDB table is configured to be always consistent.
Ensure the BatchGetltem operation is called with the ConsistentRead parameter set to false.
Enable a stream on the DynamoDB table and subscribe each device to the stream to ensure all devices receive up-to-date status information.
Ensure the BatchGetltem operation is called with the ConsistentRead parameter set to true.
Explanations:
DynamoDB tables are eventually consistent by default. Making the table “always consistent” is not possible in this context because DynamoDB does not support globally consistent data by default. Consistent reads are applied at the individual read operation level, not at the table level.
Setting the ConsistentRead parameter to false in the BatchGetItem operation actually requests eventually consistent reads, which may cause outdated data to be returned, exacerbating the issue of stale status information.
Enabling a stream on DynamoDB is useful for capturing changes to the table and notifying external systems of updates. However, this does not directly solve the issue of retrieving up-to-date data via BatchGetItem. Streams are not designed for real-time device updates in this context.
Setting the ConsistentRead parameter to true ensures that the BatchGetItem operation retrieves the most recent data available at the time of the read, resolving the issue of stale status information on the devices.
I estimate that the answer is:
Ensure the BatchGetltem operation is called with the ConsistentRead parameter set to true.