Open Stack

Hi,

Because I requested to create a topic for MidoNet, Tom Fifield has
asked me to raise awareness of mailing lists topics, and check whether
people are cool with introducing topics to the openstack-operators
list.

Topics are very similar to categories on a blog - a concept I hope
people are familiar with or can easily grasp. A blog post can be
tagged for no categories, a single category or multiple categories. If
you check out a blog, you see all blog posts by default. But you can
also click on a category and see only just blog posts that were tagged
accordingly (independent of whether it's also in other categories or
not).

Likewise, on mailing lists, if no topics are set up or you are not
subscribed to any, you receive all emails. If topics are set up and
you are subscribed to one or several, you only receive emails that are
tagged accordingly. In that case, you can also choose whether you wish
to receive mails that are not tagged for any topic at all.

An email is tagged by simply adding a tag to the subject line. Tags
are, by convention, written in square brackets and put at the
beginning of the subject. They are matched against a regexp, which is
usually kept rather simple. For example, the Nova topic on the
openstack-dev list [1] (where ~40 topics are defined) is
".*\[Nova\].*| .*\[nova\].*", thus matching all emails with either
[nova] or [Nova] anywhere in the subject line.

Hopefully, that was understandable - I'm happy to answer any follow-up
questions as good as I can. I considered adding an example, but that
would make this a much longer and more complex email and therefore I'm
worried it would defeat its purpose. Let me instead discuss the
benefits and drawbacks I see.

The main benefit is clearly, that people can choose what emails they
wish to receive. I think most people are subscribed to this list
either because they wish to help others or because they wish to learn
from others' experience. In both cases, they are probably interested
in certain topics but not in others and it would lower the number of
emails they receive - which makes it easier to pay attention to those
threads that are important to them.

The main drawback is probably that people might not tag their emails,
or tag them improperly. But I'd expect that most people who subscribe
to topics will choose to also receive those emails "just in case", so
we should be good.

Particularly in the beginning, there will only be a few topics (well,
I figure we'd start with just one and MidoNet would bite the bullet)
so people can slowly get accustomed to them. Once they are more
established, it might make sense to add (many) more, like on the
openstack-dev list.

Frankly, many people already tag all their emails (to this list as
well), even though no topics are set up (in which case they are
treated like untagged emails since they don't match any regexp). I
think we should already encourage always tagging emails, to make it
easier to establish new topics in the future.

Cheers,
Sandro

[1] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev