Code profiling and load testing Pressflow on CentOS 5

Profiling setup

• Install xdebug (see Stack installation on CentOS 5)
  • Configure with the option:

    xdebug.profiler_enable_trigger = 1
    

  • Do not enable any other profiling option.
• Install cg2dot.py (via xdebugtoolkit)
• Install graphviz
• Install ghostscript

Running load tests

• Clear out CacheGrind results from /tmp.
• Make a single request:

  ab  -n 1 -c 1 [url]&XDEBUG_PROFILE=1
  

• CacheGrind output will be on /tmp.

Processing results

1. Initial setup (do this once):

   svn co http://xdebugtoolkit.googlecode.com/svn/tags/0.1.4/xdebugtoolkit/ ~/xdebugtoolkit
   echo "export PATH=~/xdebugtoolkit:$PATH" >> ~/.bashrc
   

2. Convert the cachegrind output to a .dot file:

   cg2dot.py cachegrind.out.XYZ > cg.dot
   

3. Convert the .dot file into PDF-compatible PostScript:

   dot cg.dot -Tps2 -ocg.ps
   

4. Convert the PostScript into a PDF:

   ps2pdf13 cg.ps
   

5. The PDF will be named cg.pdf.