Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
React+Redux @ Scale
Search
Daniel Cousineau
June 26, 2017
Programming
1
330
React+Redux @ Scale
Given at QCon NYC 2017
https://qconnewyork.com/ny2017/presentation/reactredux-scale-talk
Daniel Cousineau
June 26, 2017
Tweet
Share
More Decks by Daniel Cousineau
See All by Daniel Cousineau
Time is a Social Construct
dcousineau
1
570
React @ Scale
dcousineau
0
170
Frontend Performance & You
dcousineau
0
290
Feature Flags & You
dcousineau
2
96
Reframing The Problem - DCJS July 2016
dcousineau
0
130
YAFT
dcousineau
2
150
Queues and the beanstalkd
dcousineau
1
660
How Not Writing PHP Makes You Better At PHP
dcousineau
0
380
JavaScript for PHP Developers
dcousineau
4
700
Other Decks in Programming
See All in Programming
Software Architecture
hschwentner
6
2.3k
Signals & Resource API in Angular: 3 Effective Rules for Your Architecture @BASTA 2025 in Mainz
manfredsteyer
PRO
0
120
Le côté obscur des IA génératives
pascallemerrer
0
140
明日から始めるリファクタリング
ryounasso
0
130
アメ車でサンノゼを走ってきたよ!
s_shimotori
0
220
技術的負債の正体を知って向き合う / Facing Technical Debt
irof
0
150
Serena MCPのすすめ
wadakatu
4
960
ポスターセッション: 「まっすぐ行って、右!」って言ってラズパイカーを動かしたい 〜生成AI × Raspberry Pi Pico × Gradioの試作メモ〜
komofr
0
1.2k
私はどうやって技術力を上げたのか
yusukebe
43
18k
GitHub Actions × AWS OIDC連携の仕組みと経緯を理解する
ota1022
0
250
Your Perfect Project Setup for Angular @BASTA! 2025 in Mainz
manfredsteyer
PRO
0
160
Cloudflare AgentsとAI SDKでAIエージェントを作ってみた
briete
0
140
Featured
See All Featured
Statistics for Hackers
jakevdp
799
220k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
3.1k
Become a Pro
speakerdeck
PRO
29
5.5k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
45
2.5k
Facilitating Awesome Meetings
lara
56
6.6k
Design and Strategy: How to Deal with People Who Don’t "Get" Design
morganepeng
132
19k
A designer walks into a library…
pauljervisheath
209
24k
Building an army of robots
kneath
306
46k
For a Future-Friendly Web
brad_frost
180
9.9k
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
189
55k
Large-scale JavaScript Application Architecture
addyosmani
514
110k
Side Projects
sachag
455
43k
Transcript
React+Redux @ Scale
@dcousineau
None
None
None
None
Rules
None
“Rules”
None
None
Scalability is the capability of a system, network, or process
to handle a growing amount of work, or its potential to be enlarged to accommodate that growth. – Wikipedia
Part 1: React
Rule: Components should be stateless
Reality: State is the enemy, but also inevitable
onClick(e) { const value = e.target.value; const formatted = value.toUpperCase();
this.setState({value: formatted}); }
onClick() { this.setState((previousState, currentProps) => { return { show: !previousState.show,
}; }); }
onClick(e) { this.setState({value: e.target.value}); this.props.onChange(this.state.value); }
onClick(e) { this.setState({value: e.target.value}, () => { this.props.onChange(this.state.value); }); }
Rule: Don’t use Context, it hides complexity
Reality: Sometimes complexity should be hidden
None
None
class TextCard extends React.Component { static contextTypes = { metatypes:
React.PropTypes.object, }; render() { const {cardData} = this.props; const {metatypes} = this.context; return ( <div> The following is either editable or displayed: <metatypes.text value={cardData.text} onChange={this.props.onChange} /> </div> ) } } function selectCardComponent(cardData) { switch (cardData.type) { case 'text': return TextCard; default: throw new Error(`Invalid card type ${cardData.type}`); } }
class TextCard extends React.Component { static contextTypes = { metatypes:
React.PropTypes.object, }; render() { const {cardData} = this.props; const {metatypes} = this.context; return ( <div> The following is either editable or displayed: <metatypes.text value={cardData.text} onChange={this.props.onChange} /> </div> ) } } function selectCardComponent(cardData) { switch (cardData.type) { case 'text': return TextCard; default: throw new Error(`Invalid card type ${cardData.type}`); } }
const metatypesEdit = { text: class extends React.Component { render()
{ return <input type="text" {...this.props} />; } } } const metatypesView = { text: class extends React.Component { render() { return <span>{this.props.value}</span>; } } }
class CardViewer extends React.Component { static childContextTypes = { metatypes:
React.PropTypes.object }; getChildContext() { return {metatypes: metatypesView}; } render() { const {cardData} = this.props; const CardComponent = selectCardComponent(cardData); return <CardComponent cardData={cardData} /> } }
class CardEditor extends React.Component { static childContextTypes = { metatypes:
React.PropTypes.object }; getChildContext() { return {metatypes: metatypesEdit}; } render() { const {cardData} = this.props; const CardComponent = selectCardComponent(cardData); return <CardComponent cardData={cardData} /> } }
Part 2: Redux
Rule: “Single source of truth” means all state in the
store
Reality: You can have multiple “single sources”
this.state.checked = true;
this.props.checked = true; this.props.checked = true; this.props.checked = true; this.state.checked
= true;
this.props.checked = true; this.props.checked = true; this.props.checked = true; this.props.checked
= true; checked: true connect()();
window.location.*
Rule: Side effects should happen outside the Redux cycle
Reality: This doesn’t mean you can’t have callbacks
function persistPostAction(post, callback = () => {}) { return {
type: 'PERSIST_POST', post, callback }; } function *fetchPostsSaga(action) { const status = yield putPostAPI(action.post); yield put(persistPostCompleteAction(status)); yield call(action.callback, status); } class ComposePost extends React.Component { onClickSubmit() { const {dispatch} = this.props; const {post} = this.state; dispatch(persistPostAction(post, () => this.displaySuccessBanner())); } }
class ViewPostPage extends React.Component { componentWillMount() { const {dispatch, postId}
= this.props; dispatch(fetchPostAction(postId, () => this.logPageLoadComplete())); } }
Rule: Redux stores must be normalized for performance
Reality: You must normalize to reduce complexity
https://medium.com/@dcousineau/advanced-redux-entity-normalization-f5f1fe2aefc5
{ byId: { ...entities }, keyWindows: [`${keyWindowName}`], [keyWindowName]: { ids:
['id0', ..., 'idN'], ...meta } }
{ byId: { 'a': userA, 'b': userB, 'c': userC, 'd':
userD }, keyWindows: ['browseUsers', 'allManagers'], browseUsers: { ids: ['a', 'b', 'c'], isFetching: false, page: 1, totalPages: 10, next: '/users?page=2', last: '/users?page=10' }, allManagers: { ids: ['d', 'a'], isFetching: false } }
function selectUserById(store, userId) { return store.users.byId[userId]; } function selectUsersByKeyWindow(store, keyWindow)
{ return store.users[keyWindow].ids.map(userId => selectUserById(store, userId)); }
function fetchUsers({query}, keyWindow) { return { type: FETCH_USERS, query, keyWindow
}; } function fetchManagers() { return fetchUsers({query: {isManager: true}}, 'allManager'); } function receiveEntities(entities, keyWindow) { return { type: RECEIVE_ENTITIES, entities, keyWindow }; }
function reducer(state = defaultState, action) { switch(action.type) { case FETCH_USERS:
return { ...state, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: true, query: action.query } }; case RECEIVE_ENTITIES: return { ...state, byId: { ...state.byId, ...action.entities.users.byId }, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: false, ids: action.entities.users.ids } }; } }
function reducer(state = defaultState, action) { switch(action.type) { case FETCH_USERS:
return { ...state, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: true, query: action.query } }; case RECEIVE_ENTITIES: return { ...state, byId: { ...state.byId, ...action.entities.users.byId }, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: false, ids: action.entities.users.ids } }; } }
function selectUsersAreFetching(store, keyWindow) { return !!store.users[keyWindow].isFetching; } function selectManagersAreFetching(store) {
return selectUsersAreFetching(store, 'allManagers'); }
function reducer(state = defaultState, action) { switch(action.type) { case UPDATE_USER:
return { ...state, draftsById: { ...state.draftsById, [action.user.id]: action.user } }; case RECEIVE_ENTITIES: return { ...state, byId: { ...state.byId, ...action.entities.users.byId }, draftsById: { ...omit(state.draftsById, action.entities.users.byId) }, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: false, ids: action.entities.users.ids } }; } }
function reducer(state = defaultState, action) { switch(action.type) { case UPDATE_USER:
return { ...state, draftsById: { ...state.draftsById, [action.user.id]: action.user } }; case RECEIVE_ENTITIES: return { ...state, byId: { ...state.byId, ...action.entities.users.byId }, draftsById: { ...omit(state.draftsById, action.entities.users.byId) }, keyWindows: uniq([...state.keyWindows, action.keyWindow]), [action.keyWindow]: { ...state[action.keyWindow], isFetching: false, ids: action.entities.users.ids } }; } }
function selectUserById(store, userId) { return store.users.draftsById[userId] || store.users.byId[userId]; }
function reducer(state = defaultState, action) { switch(action.type) { case UNDO_UPDATE_USER:
return { ...state, draftsById: { ...omit(state.draftsById, action.user.id), } }; } }
Part 3: Scale
Rule: Keep dependencies low to keep the application fast
Reality: Use bundling to increase PERCEIVED performance
class Routes extends React.Component { render() { return ( <Switch>
<Route exact path="/" component={require(‘../home').default} /> <Route path="/admin" component={lazy(require(‘bundle-loader?lazy&name=admin!../admin’))} /> <Route component={PageNotFound} /> </Switch> ); } }
require('bundle-loader?lazy&name=admin!../admin’)
const lazy = loader => class extends React.Component { componentWillMount()
{ loader(mod => this.setState({ Component: mod.default ? mod.default : mod }) ); } render() { const { Component } = this.state; if (Component !== null) { return <Component {...this.props} />; } else { return <div>Is Loading!</div>; } } };
None
Rule: Render up-to-date data
Reality: If you got something render it, update it later
None
None
None
None
None
None
Epilog: Scale?
Rule: Scale is bytes served, users concurrent
Reality: Scale is responding to bytes served and users concurrent
How fast can you deploy?
None
Pre: Clear homebrew & yarn caches 1. Reinstall node &
yarn via brew 2. Clone repo 3. Run yarn install 4. Run production build 1. Compile & Minify CSS 2. Compile Server via Babel 3. Compile, Minify, & Gzip via Webpack 190.64s ~3 min
<Feature name="new-feature" fallback={<OldFeatureComponent />}> <NewFeatureComponent /> </Feature>
None
Team 1 Team 2 Merge Feature A Merge Feature B
Deploy Deploy OMG ROLLBACK DEPLOY!!! Merge Feature C Merge Bugfix for A Deploy Deploy BLOCKED!!! Deploy
Team 1 Team 2 Merge Feature A Merge Feature B
Deploy Deploy Rollout Flag A Rollout Flag B OMG ROLLBACK FLAG A!!! Merge Feature C Deploy Merge Bugfix for A Deploy Rollout Flag A Rollout Flag C
Can you optimize your directory structure around team responsibilities? If
teams are organized by “product domain”, Can you organize code around product domain?
Final Thoughts
Strict rules rarely 100% apply to your application. Remembering the
purpose behind the rules is valuable.
Code behavior should be predictable and intuitable. Be realistic about
the problem you’re actually solving.
You will not get it perfect the first time. Optimize
your processes for refactoring.
Questions?