[Mageia-sysadm] questions about our infrastructure setup & costs

Mon Apr 2 18:29:59 CEST 2012

On Mon, Apr 2, 2012 at 17:49, nicolas vigier <boklm at mars-attacks.org> wrote:
+> Using paid hosting will not remove problems like bad RJ45 or switch
+> that stop working. If we want good availability, we need more servers
+> in different places.
+
+In paid hosting, (physical) server and link failure is to be directly
+handled by people that have a financial incentive to have it work. I
+expect (but may be wrong) that the availability will be higher than
+what we have today, and that it is still affordable for _some_
+services. It's not about going full speed to paid services or to spend
+unnecessarily money, it's about using what we can (it includes money)
+to improve our systems availability.
+
+The point is that: I don't know and I don't have the data to get an
+idea about that; and I'm not even sure the data needed is compiled
+somewhere at this time. And I suspect I'm not alone in this case. If I
+don't ask, someone else will later. Or even worse than that, won't
+dare to ask.
+
+That's why I'm asking for this for those two purposes: explaining more
+how it works, understanding how it could work.
+ - functional split list =>  your skills/job
+ - needs per functional unit => same
+ - dependencies between units => same [1]
+ - cost per unit in different contexts => can be spread around
+
+And yes, it may be too expensive. Or it may not. But I suspect we
+don't know, or it's not obvious enough. On the other hand, having one,
+or several server downtime like this for 2/3 days also costs a lot to
+the project (loss of time, and reputation shift).
+
+> I think it could help to have a few other servers in a different
+> datacenter, and duplicate services when it is easy to do (like ldap,
+> mirrors list, etc ...). In other cases like build system scheduler /
+> main mirror however, it's difficult to duplicate without conflicts
+> between the different servers, and cannot be done in a few minutes (or
+> hours), so I think we should migrate only in case of very long outage
+> (when we know that it will take more than a few days). Having a few
+> more servers available would help if we need to migrate some things in
+> case of big problem on one of the server.
+
+Yes.
+
+>>   * would it be possible to have the systems hosting our services to
+>> have a prefix in their fqdn with the city/country they are located in? [...]
+>>   * what do you think about maintaining a separate blog [...]
+> We are already adding posts on official blog, and mails on mailling
+> list in case of problem, so what would be the use of an other separate
+> blog for this ?
+
+Let's forget about these two.
+
+[1] take the attached .dot file; it's rough, very incomplete (missing
+subsystems, roles), probably incorrect, but it gives an idea of what
+are the nodes that need the maximum level of availability, and the
+ones that should not bother from each other, and were some decoupling
+could be made. You could even add a layer of who is using/responsible
+for what, or of where the system are. This is far more telling than a
+puppet configuration or a text file.
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