[dsc] No Data To Display at This Time

[Duane Wessels]

On Tue, 16 Sep 2008, Hoan Le wrote:

> 2.  I see the following errors in /var/log/httpd/error_log
>
> [Tue Sep 16 11:02:56 2008] [error] [client 192.168.201.35]  -stdin
> -maxrows
> 20000 -csmap  -mapfile
> /usr/local/dsc/cache/ce244e7abf1023de8b50d9675d227bb3.map.new
> -png -o /usr/local/dsc/cache/ce244e7abf1023de8b50d9675d227bb3.png.new
> at /usr/lib/perl5/site_perl/5.8.5/DSC/ploticus.pm line 422., referer:
> http://rancid.corp.webex.com/cgi-bin/dsc-grapher.pl?window=604800&node=c
> orp-dns1&plot=qtype&server=corp
>
> [Tue Sep 16 11:02:56 2008] [error] [client 192.168.201.35] Premature end
> of script headers: dsc-grapher.pl, referer:
> http://rancid.corp.webex.com/cgi-bin/dsc-gr
> apher.pl?window=604800&node=corp-dns1&plot=qtype&server=corp
>
>
> I have installed ploticus (located at /usr/local/bin/pl).

Based on your error logs it really looks like the CGI script cannot
find the ploticus program.

Since you say that it is installed then I would first make sure that
it (and all its parent directories) have permissions that allow the
CGI userid to execute it.

For example:

$ ls -ld /usr /usr/local /usr/local/bin /usr/local/bin/pl
drwxr-xr-x  18 root  wheel    512 Mar 26 08:39 /usr
drwxr-xr-x  23 root  wheel    512 Aug  4 14:31 /usr/local
drwxr-xr-x   3 root  wheel  22016 Sep 15 03:25 /usr/local/bin
-r-xr-xr-x   1 root  wheel  371804 Apr 24 20:32 /usr/local/bin/ploticus

FYI the version of ploticus that installs as 'pl' might be too old
for DSC now.  You should have at least ploticus version 2.33 and 2.40
is also available.

If you think that permissions are correct then perhaps the next step is
to add some debugging in the DSC::ploticus module as follows

Index: presenter/perllib/DSC/ploticus.pm
===================================================================
--- presenter/perllib/DSC/ploticus.pm   (revision 10393)
+++ presenter/perllib/DSC/ploticus.pm   (working copy)
@@ -411,6 +411,7 @@

  sub ploticus_begin {
         die "wrong state" unless (1 == $ploticus_state);
+       system "ls -ld /usr/local/bin/pl /usr/local/bin/ploticus 1>&2";
         my $prog = (grep {-f $_} qw(/usr/local/bin/ploticus /usr/local/bin/pl))[0];
         my $cmd = join(" ",
                 $prog,

Duane W.