Note Matt Chambers originally came up with the idea of using SVG -- I was just playing with it recently. The frontend template's <img> tags need to be changed to <embed> tags and also the graph dimensions need to be specified, for the frontend to be able to display SVGs -- also, the resulting graphs do not look exactly the same between PNG and SVG output formats.
Cheers, Bernard On 12/13/07, Jesse Becker <[EMAIL PROTECTED]> wrote: > There was a discussion on IRC recently about PNG vs. SVG output files. The > questions we had revolved around how "hard" it is to generate each format, > and also decode it as well. Lacking any hard numbers, I decided to make up > my own. :) > > All tests were run on my laptop, a Pentium-M 1.6GHz box (cpu at > full-throttle), using rrdtool 1.2.23. The .rrd files came from an recent > Ganglia build from the SVN trunk. I copied an .rrd file into a ramdisk, and > ran a shell script to benchmark creating and "rendering" PNG and SVG files. > > Creating the files was pretty simple: I just ran these two command a > thousand times (<grin>): > > rrdtool graph /dev/null -a PNG DEF:load=$FILE:sum:AVERAGE > LINE1:load#ff0000:load > rrdtool graph /dev/null -a SVG DEF:load=$FILE:sum:AVERAGE > LINE1:load#ff0000:load > > Before the loops, I ran 'dd' on the various input files to make sure they > were cached, although since the tests were run on a RAM disk, that shouldn't > matter much. > > Generating 1,000 PNG files took: > real 28.57 > user 21.89 > sys 2.29 > > Generating 1,000 SVG files took much less time: > real 4.18 > user 2.34 > sys 1.03 > > This makes quite a bit of sense. Since SVG is just XML, all that really > needs to be done is wrap some XML stuff around the datapoints. Making the > PNG actually requires requires plotting points, and generating the bitmap. > > Once we make the image files, we need to decode them. This is a bit harder, > and I couldn't think of a way to easily benchmark Firefox's SVG rendering > code. Instead, I used the 'convert' program from ImageMagick to convert the > output SVG and PPM files into the next closest thing: a PPM file. I > realize that this does not tell us anything about browser rending, and might > be completely useless. I hope, however, that we can get a rough idea of how > "hard" it is for a browser to render an SVG file relative to a PNM file. > > Thus, I ran these commands 1,000 times each: > convert -depth 8 +antialias test.png ppm:- > /dev/null > convert -depth 8 +antialias test.svg ppm:- > /dev/null > > The input files are the files created by rrdtool, with no other > manipulation. It is interesting to note that the image dimensions on the > .svg file are slightly smaller than the png: > test.png PNG 481x168 481x168+0+0 DirectClass 8-bit 15.2695kb > test.svg SVG 470x168 470x168+0+0 DirectClass 16-bit 6.28906kb > > Also note that the .svg file is less than half the size of the .png. > > The numbers > > "Decoding" PNG files: > real 47.50 > user 37.94 > sys 3.79 > > "Decoding" SVG files: > real 149.44 > user 119.52 > sys 7.34 > > So it looks like generating SVG files is clearly faster than PNG files, by > about a factor of 10 (User CPU time). On the other hand, "decoding" the > files with the 'convert' program was clearly slower at SVG files. > > The source RRD file and script ar available if anyone wants to play with > them on their own. > > Comments? > > -- > Jesse Becker > GPG Fingerprint -- BD00 7AA4 4483 AFCC 82D0 2720 0083 0931 9A2B 06A2 > ------------------------------------------------------------------------- > SF.Net email is sponsored by: > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services > for just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Ganglia-developers mailing list > Ganglia-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/ganglia-developers > > ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Ganglia-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
