alpakka cassandrasource read data from cassandra continuously

Question

We are doing some POC to read cassandra table continuosly using Alpakka CassandraSource. Following is the sample code:

final Statement stmt = new SimpleStatement("SELECT * FROM testdb.emp1").setFetchSize(20);
final CompletionStage<List<Row>> rows =  CassandraSource.create(stmt, session).runWith(Sink.seq(), materializer);
rows.thenAcceptAsync( e -> e.forEach(System.out::println));

The above code fetches the rows from emp1 table. Since this table grows continuosly we need to keep reading as soon as data available. Is there any way we can set continuous read in CassandraSource?

Answer 1

There is currently no support for continuously reading a table in Alpakka Cassandra connector. However you can make it work by wrapping CassandraSource.create in a RestartSource.withBackoff that will restart the cassandra source after it completes. More about restarting sources in the documentation.