[LON-CAPA-admin] Dynamic Plots on Debian

[Todd Ruskell]

Matt,

I'd love to send the error messages to you, but unfortunately, I no longer
get any gnuplot error messages in /var/log/apache/error_log. I see the
errors
generated by gnuplot complaining about the "gif" terminal from before I
made the changes, but they have now disappeared.  I probably need to bump
up the logging verbosity, but I'm new to this type of sysadmin.  How do I
do it?

I just logged into the server from home and tried to view a dynamically
generated plot that did not appear, and did actually get an error log
entry, but just one:

[Wed Jun 25 21:09:53 2003] [error] access to /home/httpd/html/adm/roles
failed for 138.67.58.184, reason: Cookie truskell_1055820329_csmTodd_toddl
not valid

Using Guy's directions below, gnuplot is compiled with gif supoprt.  I
checked it myself with a basic plot:
set term gif
set output "test.gif"
plot sin(x)
show output

I get a gif that both mozilla and xv have no trouble viewing.

How's that for a puzzler?

Hope your server shuffle goes well the next two days.

Todd


On Wed, 25 Jun 2003, Matthew Brian Hall wrote:

> Todd,
>
> It would be more useful to send us the error message listed in
> /var/httpd/error_log
>
> The plot.gif script should be the stock loncapa one.  Most likely
> this is a gnuplot error.  When gnuplot barfs it does so in the
> http error log.
>
> Possibly (likely) yours does not have gif support.
>
> Someday we'll move to another plotting solution and not have to deal
> with this issue.  (don't let me get started)
>
> Matthew
>
> >
> > Guy,
> >
> > I am making progress on this. . .
> >
> > I did the below, restarted both loncontrol and httpd.  Now I get this
> > when I try to view the image separately:
> >
> > The image
> > "http://poisson.mines.edu/cgi-bin/plot.gif?file=truskell_csmTodd_1056580683_27
> 86645_plot.data&output=gif" cannot be displayed, because it contains errors.
> >
> > Any more ideas?  I'd be happy to send you the perl script in plot.gif if
> > you think it'd help.
> >
> > Thanks,
> >
> > Todd
> >
> >
> >
> >
> > On Wed, 2003-06-25 at 12:25, Guy Albertelli II wrote:
> > > Hi Todd,
> > >
> > > > One problem I've run into is that dynamically generated plots don't seem
> > > > to get generated/stored properly for me.  I just get the little broken
> > > > image icon, and when I right-click on the image and try to view or
> > > > download it, not surprisingly I get a Not Found error:
> > > >
> > > > The requested URL /cgi-bin/plot.gif was not found on this server.
> > > >
> > > > So I went poking for cgi-bin, and found one here:  /home/httpd/cgi-bin,
> > > > as I think I expect.  However, it seems to have the following access
> > > > privileges:
> > >
> > > What is in you httpd.conf for the  ScriptAlias?
> > >
> > > It should either not be set in there (and thus use the value
> > > loncapa_apache.conf sets) or set to
> > >
> > > ScriptAlias /cgi-bin/ "/home/httpd/cgi-bin/"
> > >
> > >
> > > It that is correct, can you look for error messages in
> > > /var/log/apache/error.log  that mention plot.gif?
> > >
> > >
> > > It most likely would be complaining about not being able to generate
> > > gifs.
> > >
> > > The easiest solution to solve this is likely (as root):
> > >
> > > 1) apt-get remove libgd-dev gnuplot
> > > 2) apt-get install libgd-gif1 libgd-gif1-dev
> > > 3) wget http://aleron.dl.sourceforge.net/sourceforge/gnuplot/gnuplot-3.7.3.t
> ar.gz
> > > 4) tar xzvf gnuplot-3.7.3.tar.gz
> > > 5) cd gnuplot-3.7.3
> > > 6) ./configure --with-gd
> > > 7) make
> > > 8) make install
> > >
> > >
> > > --
> > > guy at albertelli.com  LON-CAPA Developer  0-7-6-7-
> > > _______________________________________________
> > > LON-CAPA-admin mailing list
> > > LON-CAPA-admin at mail.lon-capa.org
> > > http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
> > >
> >
> >
> > _______________________________________________
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> >
>
>
> --
> ------------------------------------------------------------------
> Matthew Hall           LON-CAPA developer         hallmat3 at msu.edu
> 123 North Kedzie Hall                    Michigan State University
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