[LAU] GNU Denemo chokes a dual core 2 GB server

[Christian Einfeldt]

hi

My question is fairly long to explain, but simple to summarize:  why are we
experiencing delays in playing music compositions using GNU Denemo under
Edubuntu over a GB network that should be performing better, and what can we
do to solve the problem without spending any money?

I am a volunteer supporting a public middle school with FOSS.  We have a
brand new dual core server with 2 GB of RAM whose only purpose in life is to
support 24 chubby clients running edubuntu.  The thin clients have at least
256 MB of RAM, and most of them have swap space on their hard drive also,
although some of them are true thin clients in that the hd has no swap and
is basically a vestige.  I am told that we have a gigabyte network.  The
server feeds the signal to the first 18 clients through one GB switch, and
then that switch feeds another identical switch with services about 6 more
clients.

Our problem is that when we use GNU Denemo to play the short little
compositions that the students write in class, we can have only one student
play his / her composition at a time or the system is choked, meaning that
it lags.  More specifically, all of the students find that their GNOME
desktops are almost completely non-responsive to the mouse.  The mouse still
moves, but programs launch very slowly for about 5 mins, at which time the
choke point is presumably cleared, and then one student can again play his /
her composition.  It might be possible for, say, 2 students or maybe even
three students to play their music; but we don't know where that stress
point is.

And, in some ways, it doesn't even make sense to slowly add students and
have them play music, simply because some people who have heard of this
problem in passing furrow their brow and say that we shouldn't be having
these problems.

We are, of course, going to be trying to get more RAM in the clients; and
swap for all of the clients; and we have thought of running GNU Denomo
natively on each of the clients by booting them as stand alone work
stations.  But I am a volunteer, and this inner city school has absolutely
no budget for a real tech support person, and all of the teachers already
are at work by 6:50 a.m., and they usually stay until 6:30 p.m., and then
each of the teachers is expected to be available to field phone calls at
home until 8 p.m.  All of this might sound kind of drastic, but our students
typically come to this school of 290 students under-performing their grade
level by 2 grade levels, but leave the school as 8th graders typically
performing at or above grade level.  Seventy-five (75%) of our students come
from households below the federal poverty guidelines.  65% of our students
are African American; 17% are Latino; 10% are Asian; and 8% are Caucasian.
Despite the life challenges facing our students, last year our students
tested in first place (as a student body) based on standardized testing.  So
this school is succeeding in many ways, but they are really struggling in
terms of technology, and that is all because of funding shortfalls.

Coincidentally, the students spend no time here on Windows boxes, except for
occasionally random Internet browsing on a teacher's Windows box.  But that
is the exception, because, as you can imagine, the teachers don't want the
students accessing their computers.  So when the students are not in the
lab, they are using PClinuxOS boxes in several of the classrooms to do their
Internet research.

Overall, this school is making miracles with no funding.  I am hoping to
move the whole school to FOSS eventually, but of course there is still a lot
of work to be done.  Thus far, the music teacher is fairly impressed with
the ability of students to compose music on GNU Denemo, but she would just
like to be able to have all of the students listen to their compositions at
the same time.  Typically, these compositions are no more than, say, 6 or 10
bars long, just enough to get the students familiar with the basics of
scales, rests, note duration, tempo, beat, etc.  Just the basics.

Thanks in advance for the help.

-- 
Christian Einfeldt,
Producer, The Digital Tipping
Point<http://archive.org/details/digitaltippingpoint>
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