One key per row: turning a Cassandra primary key into a vector key
The same row arrives as strings from the stream and as typed values from CQL. If they don't produce the same key, the index quietly holds two vectors for one row.
Dev notes
What broke when we ran it against real AWS
A 60-request-a-minute quota nobody can raise, a shutdown that never finished, and a 12-minute wait we hadn't planned for.
Why we forked the AWS sample, and what we changed
AWS's sample connector is a good start and a risky finish. Five problems, each invisible until data goes missing.