If I may add, people that wish to upgrade from 0.6 to 0.7 are also 
strongly encouraged to go directly to 0.7.3, otherwise they would 
be exposed to the bug that 0.7.3 fixes.


On Fri, Mar 4, 2011 at 10:52 PM, Eric Evans <eevans@rackspace.com> wrote:

It's only been a couple of weeks since the last release, but a rather
nasty bug (some details here[1]) has since been fixed, and it seemed
best to get that out to folks sooner rather than later.

The issue in question is well explained in the release notes[3], but the
TL;DR is that users of 0.7.1 and 0.7.2 are encouraged to upgrade to
0.7.3, and run `nodetool scrub' to address bloom filters that may have
been incorrectly generated when compacting older SSTables.

There have been a number of other fixes since 0.7.2 as well, so even if
you're running < 0.7.1, it's still worth the update[5,6].

As always, be sure to read through all of the changes[2] and release
notes[3]. Report any problems you find[4], and if you have any
questions, don't hesitate to ask.

[1]: https://issues.apache.org/jira/browse/CASSANDRA-2217
[2]: http://goo.gl/hX02M (CHANGES.txt)
[3]: http://goo.gl/HXlNH (NEWS.txt)
[4]: https://issues.apache.org/jira/browse/CASSANDRA
[5]: http://cassandra.apache.org/download
[6]: http://wiki.apache.org/cassandra/DebianPackaging

Eric Evans