How 58.com Scaled Its IM Platform to Billions of Requests: Architecture & Push Strategies

58.com Bangbang is a classified information platform covering real estate, used‑car, recruitment, and more, processing over 1 billion IM messages and 3 billion business operations daily, with more than 1 million concurrent users, posing serious infrastructure challenges.

58.com Bangbang Technical Architecture

System Start: Traditional IM

The initial system was a traditional instant‑messaging service. Its architecture is divided into four layers: access, logic, routing, and data.

Access Layer : Handles massive PC, mobile, and web client connections, consolidates them into a few long connections, and forwards requests to the logic layer.

Logic Layer : Processes business logic such as permission checks, adding friends, and sending messages.

Routing Layer : Manages session‑related data (online status, login IP, etc.) that changes rapidly and stores it in memory.

Data Layer : Acts as a data middleware, abstracting underlying RDBMS and NoSQL differences to simplify key data storage.

System Evolution: Third‑Party Business Integration

As the business grew, Bangbang transformed into a comprehensive merchant mobile management platform, integrating services like real estate and recruitment. Third‑party services are accessed via HTTP without long connections, accelerating development but creating tight client‑service coupling, costly client upgrades, and compatibility issues.

System Maturity: Client Lightweight

A Bangbang WebService layer was added to reduce client coupling with third‑party services, allowing client apps to remain stable even when backend services change.

O2O Core Technology Analysis

For mobile O2O, long connections, LBS, and push notifications are crucial.

1. Main Push Methods

Client polling (pull): Clients periodically request updates; simple architecture but low real‑time performance and higher power consumption.

SMS push: Sends messages via SMS; offers high real‑time and delivery rates but incurs high costs.

Server‑initiated long‑connection (push): Current mainstream method providing good real‑time performance with low power usage.

2. Platform‑specific Implementations

iOS Platform : iOS apps cannot run background services, so push relies exclusively on Apple’s APNS channel.

Android Platform : Android allows multiple options. Google’s C2DM (now deprecated) can be used, as can XMPP‑based open‑source protocols or various third‑party push services. C2DM suffers from server location restrictions and reliability issues; XMPP lacks ACK mechanisms and can become unstable under high load.

Third‑party push products differ in delivery rates and latency. 58.com combines several providers and selects the optimal one per device after data analysis to improve delivery and real‑time performance.