Get Started with Live Commerce - Architecture of Mercari Channel - 2018.10.24 ライブ配信 Meet up 〜メルカリ × SHOWROOM〜 @oqrusk

Yusuke OKURA - @oqrusk - Johnny • Mercari • Backend Engineer (since 2018.03) • Live & Fashion project • Tech Lead (since 2018.07) • Experience • Internal IT Dept @ Large Frozen Food Company • Java Engineer @ Food EC Venture • Backend Engineer @ Navigation Service Venture • SRE @ Family Album Service Startup

• Live Commerce Service in mercari • Anyone can buy and sell on Live! • Service Launch • since 2017.07 • Release for Business who sell • since 2017.12 • UI Renewal ←New! • since 2018.10 About Mercari Channel

Architecture

• Media • Live Streaming • Transcoding • Contents Delivery • Communication • Real Time • Interactive • Many-to-Many • Shopping • Listing • Sales Promotion • Price Negotiation Functions of Live Commerce

Components of Mercari Channel Viewer’s Info Notification Comments Likes Stamps Video & Sound Product

Media ● Protocol ○ Live stream : RTMP ○ View: HLS ● Transcode ○ 1 source to 3 output ■ Quality (High/Mid/Low) ■ Adaptive Bitrate Stream ● Delivery ○ CDN ○ latency 10+sec

Communication ● Motivator ○ Comments ○ Stamps ○ Likes ○ Viewer Count ○ Notifications ● Many-to-Many Broadcast ● Real Time Sync

Shopping ● Real Time Update ○ New Listing ○ Price Change ○ Stock Inventory ● One-to-Many Broadcast ● Picture in Picture ○ Stay in Live

Few Resources & Tight Schedule 2 Months From Scratch 4 Engineers 2 Backend 1 iOS 1 Android

Using Cloud Services ● Cloud Hosted Streaming Package ○ Transcoder ○ Storage ○ CDN ○ Client SDK ● Performance ○ latency 10+ sec ● Cloud Hosted Database ○ NoSQL ○ Real time synchronize ● Client SDK ● Performance ○ 100k connections ○ 1000 query / sec

Architecture SHOPPING

Operation

Daily Operation - Manual • 24/7 Manual censoring • comments • content • speech • picture • Alert censor words • Report from customers

Emergency Operation - Monitoring System • Chat Ops • Monitoring System • Stackdriver • Mackerel • Kibana • Alerting • Slackbot with Zappier

Recap • Live Commerce Functions • Media • Communication • Shopping • Using Cloud Service • Wowza Streaming Cloud • Firebase Realtime Database • Operation • Manual censoring • Slack based monitoring

Thank you