follow your code: node tracing

Follow your code: Node/V8 tracing

Gireesh Punathil, 26th Aug 2016

Wednesday, May 3, 2023

EclipseSummit 2016, Bangalore Follow your code: Node / V8 tracing

Agenda♨Overview of Node/V8 Runtime environment

♨Eclipse as a Node.js development platform

♨Debug Server-side Javascript through Browser

♨Overview of in-built tracing

♨Top tracing options in Node/V8



Philosophy of event-driven programmingTraditional synchronous multi-threaded model

Asynchronous event driven model

Source: http://bit.ly/2baQkwp


EclipseSummit 2016, Bangalore Follow your code: Node / V8 tracing 4

dns

file

net

timer

Hello event driven world!

=> dnscb127.0.0.1

=> fscbName: node …

=> netcb<html> …

=> timercbI am timed out

Anatomy of event loop



var a = 10var b = ‘g’var c = new Object()

res.on(‘data’, function(d) { data += d});

dynamic typing

async, event driven

born for the cloud

isomorphic

single threaded

Major features of Node.js



Eclipse for Node.js

Node.js a first class citizen in Eclipse

Nodeclipse is the Eclipse plugin for the Node.js

Professional Node.js development made easy, productive and a cool experience

Syntax high-lighting, in-built semantic validation, live debugging, Content assist and much more

Active community support



Prepare Eclipse for Node.js Get the latest Node.js

Get the latest Java

Get the latest Eclipse

In Eclipse install new software

Switch to Node perspective



Debug Server side script in the browser♨Server side code can be very large

♨Quite difficult to follow the control flow and logic

♨console logging very inefficient, and bad practice

♨Native debugging is even more complex

♨At the same time, vetting critical for reliable production



Debug Server side script in the browser♨Install a debugger module

♨Start the application in the debugger

♨Get the debugger port, and access it in the Browser

♨Start following the code!



Tracing the scriptPurposeTrace Javascript functions with input and output

Output

Syntax (Heavy profile)



Log APIsPurposeCollect all the V8 API calls emanating from the application

Output

Syntax



Log Script executionPurposeCollect all the script / function information as and when they are loaded / compiled / recompiled

Output

Syntax



Tracing Garbage CollectionPurposeTrace load in the v8 heap and collection patterns

Output

Syntax

Scavenge collection

Mark-sweep collection



Tracing Call SequencePurposeTrace the code flow path on uncaught exception scenarios

Output

Syntax



Tracing CompilationPurposeTrace optimize compilation decisions and their reasons

Output

Syntax



Tracing Compiled CodePurposeTrace the generated native code for the Javascript source

Output

Syntax



Selectively disable CompilationPurposeIdentify and omit optimize compilation on problematic methods

Output

Syntax



Profile the application for Performance♨Manual profiling inefficient and impractical

♨Adding time measurement cause further burden

♨Native profilers do not provide Javascript insights

♨Large applications often contain performance hideouts

♨Precise performance measures is a hallmark qualifier for software modules



Profile with v8 profiler, view with tick

♨Run the code inside light-weight profiler

♨Rename the generated log file to v8.log

♨Install tick module

♨Post-process the profile log

♨Start analyzing the profile!



For further learning♨Learn Node.js: https://nodejs.org/en/docs/

♨Learn Javascript: http://www.w3schools.com/js/

♨Learn V8: https://developers.google.com/v8/intro

♨Learn Nodeclipse: http://www.nodeclipse.org

♨Chrome developer tools: https://developer.chrome.com/devtools

https://nodejs.org/en/docs/

https://nodejs.org/en/docs/

http://www.w3schools.com/js/

http://www.w3schools.com/js/

https://developers.google.com/v8/intro

https://developers.google.com/v8/intro

http://www.nodeclipse.org/

http://www.nodeclipse.org/

https://developer.chrome.com/devtools

https://developer.chrome.com/devtools

follow your code: node tracing

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