FC 3 -- Ready for Production Deploymnet??

[Matt Morgan]

On Mon, 28 Feb 2005 11:38:17 -0500, Tim Holmes <tholmes at mcaschool.net> wrote:
> Good Morning Folks:
> 
> I have just finished loading my first FC3 box, and the updates are
> running right now.  I will be testing this box for a period of time, but
> what I am wondering is if FC3 is ready for production deployment at this
> point, or if I should wait for a further period of development.  We are
> mostly a windows shop, and my normal time table is to not deploy an
> operating system until it has gone through the first service pack
> update, but there are exceptions to this rule.  I am newer to using
> Fedora and I don't have a good time table established for deployment.  I
> have 2 webservers (apache) a database server (MySQL) and a file server
> (samba) currently deployed, as well as a Nagios box, one running cacti
> and one that will be shortly getting mailman
> 
> Your insights and thoughts would be appreciated

This list entertains many questions about Fedora Core's stability.
Most of the questions belie a misunderstanding of what "stability"
means in Fedora Core's terms. So I'm writing back with a longer
message I've been thinking about sending in to the list for a while.
Thanks for the opportunity!

Stability generally means two things:

1) doesn't crash/break.
2) doesn't change.

The thing is, these two things cannot be completely independent of one another.

Fedora, by design, aims for as much of #1 as possible, while going for
as little of #2 as is necessary. That is, Fedora changes a lot. Most
of the time this is OK but when there are major updates to some part
of the system, the changes can result in problems for almost anyone
who isn't staying on top of them. When an update gets into Fedora
Core, chances are it doesn't have true bugs (the OOo update earlier
this month was an exception), but it will change things and that's not
necessarily what you want. The problems will be recoverable, but ask
this question: can your server be down for an hour, once in a while,
while you turn back the updates-clock a little bit?

I would contrast Fedora's approach with Debian's (the best
counter-example), where policy dictates that updates to the system go
for both kinds of stability. That is, updates are designed not to
change the system at all, whenever it's possible. So, for example,
updates are divided up into "security" updates, which only fix bugs
that expose potential exploits, and other updates that include feature
changes that may require configuration file updates, etc. As far as I
know, RedHat Enterprise Linux and its free derivatives (WBEL, Centos
have been given as examples) do not enforce this same policy but
instead work in a different way toward greater stability: updates are
much more heavily tested before release than are Fedora updates
(partly they are tested against Fedora Core--that is, Fedora gets the
updates first, and if they work out, they end up in RHEL).

So what does this mean? Basically: if you can get a Fedora Core system
to do what you want it to do, it will probably continue to do that
indefinitely, until something changes. In some circumstances your
system will run forever (my compatriot here at work has a Fedora Core
1 machine that's been up for 400+ days, and that's a desktop he pounds
on daily). But for a web server, you're going to want to stay on top
of updates and that will take a little bit of governance and
occasional problem-solving. You can't just "set it and forget it."

It may sound like I'm recommending against Fedora in your case, but
I'm not. I think Fedora is great. We don't run it on our servers, but
that's because we're understaffed so we favor stability over features,
and that's Debian's strength. We can turn on security updates, turn
off all other updates, and rarely worry about those servers again. But
this is a pretty high-level strategic decision and it wouldn't really
take a lot more effort to use FC3 instead.

Good luck,
Matt