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From: Sylvain Lebresne <sylvain@datastax.com>
Date: Wed, 30 Nov 2011 18:16:51 +0100
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 <CAKkz8Q3rWWReGo0nqqcCG3rF=6e4b3eS9z9F5izTCg5pqtCSLw@mail.gmail.com>
Subject: Distributed testing
To: dev@cassandra.apache.org
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Cassandra needs distributed regression testing. The current unit tests and
so-called 'system' tests are great, but limited in scope for a distributed
system.  As pointed by others very recently, this can only help towards the
goal of having bullet-proof releases (this is obviously not enough, but it's
needed all the same).

We have an attempt at distributed tests in-tree but it never caught up.
Amongst the reason, is probably the fact that they are using whirr and
thus require an EC2 or Rackspace account.

To try to solve that problem, Datastax has developed a small distributed test
framework called cassandra-dtest (dtest for short). It is written in python
and uses nosetests and ccm (https://github.com/pcmanus/ccm). It is
open-source and available at https://github.com/riptano/cassandra-dtest. The
number of tests is yet limited but already far exceed those of the in-tree
distributed tests. It include in particular multi-DC tests and upgrade tests.

This is very much young code and all inputs will be greatly appreciated. The
clear goal however is that unless someone has anything better to propose, we
use this as the default distributed test framework for Cassandra. Which means
getting into the habit of requiring a regression test (unit or distributed)
with each bug fix.

--
Sylvain