[Server-devel] Server Admin Interface

[John Watlington]

On Feb 27, 2008, at 11:23 PM, Martin Langhoff wrote:

> On Thu, Feb 28, 2008 at 5:15 PM, John Watlington <wad at laptop.org>  
> wrote:
>>  What would an administrative interface for the school server  
>> provide ?
>
> I have been thinking a bit about this. The base XS has to be
> functional - and offer services to the XOs - without any
> configuration. One of the principles we have is that adults are very
> likely to not understand a thing about computers, and while the kids
> will figure out the XOs, the XS has to provide things like backup and
> presence services automagically.
>
> If the server *is* configured -- it will be in most cases, but perhaps
> long after it has been deployed -- of course we can do lots of things
> ;-)
>
>>  - change the domain name of the school
>>     Coming in tonight's build to handle the mess of file editing
>>  currently needed.
>>     This should only be done once.   If done after ejabberd starts up
>>  for the first time,
>>     ejabberd will crash and refuse to run.
>
> Interesting - we should be able to handle "late" naming of the school.

Yeah, so one would think.   ejabberd is the only barrier to being able
to do so at this time.   We can contract to get an erlang script
for fixing up the mnesia database if we continue to use ejabberd.

But once laptops are registered with a school, they are registered to
the FQDN of the school.   If you change the domain name
you will currently orphan a lot of laptops.

Longer term, I want to see a datastore architecture that doesn't have
this limitation.  A school server is just an intermediate cache of a  
student's
data.   Moving to another school (or between schools) thus works just
fine (with a long latency when accessing data not already cached on a
particular school's servers), as does operation after graduation from  
a school.
But that is still in the formative stages (and requires countries to  
foot the
bill for large centralized data centers.)

>>  - configure the LAN networking.  Done automatically on first boot
>
> Yes.
>
>>  - configure the role of the server (is it the principal server in a
>>  school, running primary
>>     versions of services ? or an auxiliary server just running the
>>  distributed services ?
>>     This should be easily changeable (perhaps even automatic in the
>>  case of a failure of
>>     the principal server.)
>
> I think we should have an automatic mechanism that is - at the same
> time - stable.
    A manual override would work fine for starters.   It's pretty  
stable !

   I would prefer to spend the effort improving the reliability of  
the servers
   than working on automatic switchover methods.   One easy modification
   planned is to move the core OS and services onto a Flash disk, so  
that
   networking continues to operate even after a disk failure.

>>  - There needs to be an easy way to configure the WAN interface.  We
>>  don't have a handle yet
>>     on all the different interfaces we might have to work with
>>  (PPPoE ?  PPPoA ?).
>>     This might change at any time.
>
> Agreed. Here it is impossible to autodiscover in all cases, so try
> DHCP, and if it doesn't work we'll need a myriad of options.
>
>>  There is a whole level of "school interface" needed (adding/removing
>>  students, fixing
>>  things after a student's laptop is replaced, etc) but that is
>>  different from the admin interface
>>  and needs much more careful interface design.
>
> Yep. That's where I see Moodle or something similar for a UI. Once the
> XS has seen the student laptop, rather than 'add/remove' what I thin
> we want is to "name" the student. It can also be the UI to access
> archived backups and associating a "new" laptop to a known student (in
> the laptop-replacement case).

Sounds like the right idea.

wad