Fallthrough Retry Policy

The Fallthrough retry policy prevents the driver from retrying queries when they failed.

This strategy should be used when the retry policy has to be implemented in business code.

Fallthrough policy is used explicitly

Given

a running cassandra cluster with schema:

CREATE KEYSPACE simplex WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 3};
USE simplex;
CREATE TABLE songs (
  id uuid PRIMARY KEY,
  title text,
  album text,
  artist text,
  tags set<text>,
  data blob
);

And

the following example:

require 'cassandra'

cluster = Cassandra.cluster(retry_policy: Cassandra::Retry::Policies::Fallthrough.new)
session = cluster.connect('simplex')

begin
  session.execute('SELECT * FROM songs', consistency: :all)
  puts "failed"
rescue Cassandra::Errors::UnavailableError => e
  puts "success"
end

When

node 3 stops

And

it is executed

Then

its output should contain:

success