Paresh GoelAll things Android, Hike Messenger

Building for India.

Gearing for 100 Million users

2

LAUNCH: DEC’2012

AUG’14: 35M USERS IN 20 MONTHS

INDIA: 90% OF USERBASE

3

Days

WHERE WE ARE

0.

12.5

25.

37.5

50.

62.5

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500

Hike Twitter Facebook

4

Days

0.

12.5

25.

37.5

50.

62.5

0 150 300 450 600 750 900 1050 1200 1350 1500Hike Twitter Facebook

WHERE WE ARE

BIGGEST INDIAN MOBILE

APP

10 BILLION+ MESSAGES

PER MONTH

What does Building for India mean?

What does Building for India mean, Technically ?

• Network optimisation.

• Catering to low-end devices.

Network optimisations

• Most people in India use sachet data packs.

• It costs INR 3 / MB.

Client-Server Protocol

• Has to be persistent.

• Takes care of flaky network condition.

• Consumes lesser bandwidth.

MQTT (Message Queue

Telemetry Transport)

• Network protocol for broadcasting and

listening for information over network.

• Lightweight: Header to Message ratio is less.

• Publish / Subscribe mechanism.

• Support for QoS Levels.

MQTT Message Format

• A MQTT topology has a MQTT server and a

MQTT client.

• The protocol works by exchanging a series of

MQTT Control Packets.

MQTT Control Packet

Structure

Client Server

CONNECT

CONACK

SUBSCRIBE

SUBACK

PUBLISH

PUBACK

DISCONNECT

Client Server

CONNECT

CONACK

SUBSCRIBE

SUBACK

PUBLISH

PUBACK

DISCONNECT

Client Server

CONNECT

CONACK

PUBLISH

PUBACK

DISCONNECT

Auto-subscribe

QoS Levels

• At most once. QoS=0

• At least once. QoS=1

• Exactly once. QoS=2

Active and Passive timeouts.

• GCM Push for passive state.

• Aggressive timeouts for active state.

File Transfer

Optimisations.

3 BILLION+ STICKERSPER MONTH

LOCALIZED STICKERSINDIA

Avoid transfer when you can.

Don’t load images on scroll.

Client Server

MD5

Key

Publish with key

MD5 checksum

Client 1 Server Client 2

Publish with Sticker Id

Publish with Sticker Id

use local file path

Use Unique Id

Client 1 Server Client 2

Publish with Sticker Id

Publish with Sticker Id

Request File for Sticker Id

File for Sticker IdAdd Entry

Transfer based on destination dpi.

Chunk sizes to cater to a flaky network connectivity.

Multi-threaded download.

Still playing: Chunk size could vary on actual speed at runtime.

Feature Optimisations

App decisions are also based on minimising

bandwidth consumption.

In India, users may be offline for long periods of

time.

We send pending messages in one bulk packet.

This reduces headers and corresponding Ack

packets.

Bulk Packet

Last Seen

We moved into a subscription rather than a

broadcast mechanism.

Summary

• Network Optimisations should be top priority

• Choose bandwidth-optimised network

protocol.

• File Transfer - MD5, resolution based.

• Feature decisions - optimise for network.

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38

THANK YOUGO BIG OR GO HOME

PARESH GOEL,HIKE MESSENGER

paresh@hike.in

hikeathon@hike.in

19-21 Dec

Your code is worth a Million !