In CGI mode, munin-html calculates incorrect graph dimensions

[Michael]

Binary package hint: munin

I'm guessing calculate_png_size() hasn't been updated for recent versions of rrdtool. The attached patch results in the correct PNG width/height being calculated.

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 9.04
Package: munin 1.2.6-8ubuntu3 [modified: usr/bin/munin-cron]
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_AU
 SHELL=/bin/bash
SourcePackage: munin
Uname: Linux 2.6.28-15-generic x86_64

[Chuck Short (zulcss)]

Hi,

Thanks for the patch however can you give a bit more explanation.

Thanks
chuck

[Michael (miiichael)]

On Thu, Oct 08, 2009 at 04:59:50PM -0000, Chuck Short wrote:
> Thanks for the patch however can you give a bit more explanation.

I'm not sure how else to explain it other than to say without the patch,
the calculated PNG dimensions are different to the actual PNG dimensions,
resulting in the graphs being scaled in ugly ways (missing or duplicated
rows/columns of pixels) by the web browser.

Non-CGI mode (the default) is unaffected because PNG dimensions are instead
obtained from the actual PNGs themselves.

At the very least, you should be able to tell that rows of text are 12
pixels each and not 15...

HTH,

-MD

--
-------------------------------------------------------------------------------
Michael Deegan Hugaholic http://wibble.darktech.org/gallery/
------------------------- Nyy Tybel Gb Gur Ulcabgbnq! -------------------------

[Chuck Short (zulcss)]

Thank you for your bug report. This bug has been reported to the developers of the software. You can track it and make comments at:

http://munin.projects.linpro.no/ticket/726

[janl (janl)]

Hi,

I'm the upstream project-manager-hacker-whatever. I closed the ticket as "wontfix" with this reason:

---
Hi,

thanks for the patch, but we won't apply. Also munin 1.4 is just around the corner so our effort is going into that.

In 1.4 we're using the get_png_size procedure instead. Calculating the right geometry is not a very good idea as it will change whenever a new version of rrd comes out (1.0, 1.1, 1.2, 1.3,. ...), whenever the font is changed (Debian is using a different font than the original release), and probably also the phase of the moon.

Suggest you use the get_png_size procedure instead and wait for 1.4 from upstream.

Nicolai
---

The suggested fix is very easy and will handle 99% of all cases as graphs are seldom resized. In any case it will be noticably better than what the cgi user is seeing now.

 Debian should have a 1.4 package rather quickly after the release.

[Michael (miiichael)]

On Thu, Oct 29, 2009 at 09:16:55PM -0000, janlOld wrote:
> I'm the upstream project-manager-hacker-whatever. I closed the ticket as
> "wontfix" with this reason:
>
> ---
[snip]
> ---
>
> The suggested fix is very easy and will handle 99% of all cases as
> graphs are seldom resized. In any case it will be noticably better than
> what the cgi user is seeing now.

After reading #480 I'm afraid I'm inclined to agree with you. Oh well. :P

I guess I shall hope that 1.4 makes it for squeeze/lucid.

Thanks,

-MD

--
-------------------------------------------------------------------------------
Michael Deegan Hugaholic http://wibble.darktech.org/gallery/
------------------------- Nyy Tybel Gb Gur Ulcabgbnq! -------------------------

[Chuck Short (zulcss)]

Im marking this as wont fix for right now.

Regards
chuck