nprof

small promise interface to v8-profiler functions

install

npm i --save nprof

usage

var nprof = require('nprof');

nprof.takeMemorySnapshot('/tmp/snapshots')
    .then((info) => {})
    .catch((error) => {});

nprof.cpuProfile('/tmp/snapshots', 2000)
    .then((info) => {})
    .catch((error) => {});

api

takeMemorySnapshot(snapshotPath, options) : Promise

• snapshotPath - path to directory (nprof generate filenames)
• options
  • filepath - set this option with filepath, if you need your own filename

take memory snapshot and save to snapshotPath

filename mask

${snapshotPath}/v8.cpu.2016-09-20T13-56-53-936.cpuprofile'

cpuProfile(snapshotPath, timeout, options) : Promise

• snapshotPath - path to directory (nprof generate filenames, see)
• timeout - timeout in ms
• options
  • filepath - set this option with filepath, if you need your own filepath and filename

start cpu profiling, stop after timeout and save to snapshotPath

filename mask

${snapshotPath}/v8.cpu.2016-09-20T13-56-53-93.timeout.' + timeout + '.cpuprofile'

startCpuProfile()

start cpu profiling

stopCpuProfile() : CpuProfile

stop cpu proflile

saveCpuProfile(profile, snapshotPath, options) : Promise

save profile to file

• profile - profile object
• snapshotPath - path to directory (nprof generate filenames)
• options
  • filepath - set this option with filepath, if you need your own filename

express.js helper

express.js profiling helper

usage

// logger is you logger with info, warn and error methods

var nprofRegister = require('nprof/express/register');

var app = express();

var nprofConfig = {
    snapshotPath: '/tmp/snapshots'
};

nprofRegister(logger, app, nprofConfig);

REST API

POST /_service/profile/cpu?timeout={int}

• timeout - profile timeout, length of profiling in ms, default = 5000

profile CPU, save to nprofConfig.snapshotPath

POST /_service/profile/cpu/start

start cpu profiling until POST /_profile/cpu/stop not executed

POST /_service/profile/cpu/stop

stop cpu profiling and save to nprofConfig.snapshotPath

POST /_service/profile/mem

take memory snapshot and save to nprofConfig.snapshotPath

GET /_service/profile/mem/usage

scale GET-param can be number or string (kb, mb, gb)

get actual memory usage via process.memoryUsage

POST /_service/profile/gc/start

exec global.gc() if process started with --expose-gc option

return before and after process.memoryUsage

GET /_service/profile/status

return memory usage and event loop delay

you can add your own status metrics via config.statusFn hook function

see examples/status for more information

LICENSE

MIT