Talk about the different alternatives for debugging and profiling Node.js applications

1. Debugging & profiling
Node.js
@tomasperezv

2. https://github.com/tomasperezv/node-debug-and-profiling

3. Why
minimize console.log
avoid code changes
…
...

4. Debugging
node-inspector

5. Profiling
node --prof file.js
node-tick-processor v8.log
https://code.google.com/p/v8/wiki/V8Profiler

6. Profiling
node-time

7. Profiling
node-time
npm install nodetime
require('nodetime').profile({
accountKey: 'account_key',
appName: 'application_name'
});
// Your app here

8. Profiling
https://github.com/baryshev/look
npm install look
require('look').start();
// Your app here

9. Profiling
dtrace!
http://cs.brown.edu/~dap/helloworld.svg

10. Profiling
// Show system calls made by a running node process
dtrace -n ‘syscall:::entry/pid==26442/{}’
// Count system calls made by a running node process
dtrace -n 'syscall:::entry/execname == "node"/{@[probefunc]=count();}'
dtrace

11. Profiling
dtrace + stackvis = flamegraph
dtrace -n 'profile-97/execname == "node" && arg1/{ @[jstack(150, 8000)] =
count(); } tick-30s { exit(0); }' > stacks.out
gc++filt < stacks.out > demangled.out