jwinter

Debugging ruby performance - Aman Gupta

C, Linux, networks, cpu, and memory usage

• lsof -nPp <pid>
• tcpdump
• write the data to a file, load it up in wireshark
• strace, trace systems calls and signals (jump into kernelspace)
• SIGVTALRM, ruby 1.8 every 10msec to switch threads (green threads)
• posix-spawn instead of fork-exec, check out posix-spawn gem
• ltrace

– ltrace -c ruby foo.rb # summary mode

jwinter

wget http://rubyforge.org/frs/download.php/70304/ruby-debug-base-0.10.3.2-java.gem
gem install ruby-debug-base-0.10.3.2-java.gem 
gem install columnize
rm ruby-debug-base-0.10.3.2-java.gem 
gem install ruby-debug --ignore-dependencies

jwinter

(defn when-its-one []
          (loop []
              (if (= 1 (rand-int 2000))
                1
                [(println "foo")
                 (recur)])))