Data Redundancy at Your Fingertips, Zero-Downtime Failover: GBase Powers the Smart Upgrade of Tianjin’s Z4 Metro Line

Published on 2026-04-01

On January 18, 2026, Phase 1 of Tianjin Rail Transit Z4 Line officially commenced operation. This 43.7-kilometer backbone line with 24 stations traverses the Binhai New Area, designed to carry over 5 million passengers daily.

With such massive passenger flow, the automatic fare collection (AFC) system must interact in real time with multiple systems including Tianjin ACC, Binhai MLC, and the smart payment platform to enable a unified “One Ticket” network.GBase’s high-availability architecture and strong concurrent processing capabilities provide stable and reliable data support for the Z4 Line AFC system, ensuring smooth passage for every QR code scan, card tap, or face recognition.

Interconnection: Multiple Challenges for the AFC System

Smooth rail transit operation relies on the precise support of the AFC system. The Z4 Line AFC system must not only operate independently but also seamlessly interface with multiple systems such as Tianjin Urban Rail Transit Clearing Center (ACC), Binhai MLC, Smart Payment Platform (SPT), Line-Network Standardized Terminal Device Management Cloud Platform (IMT), and the Face Recognition Platform to achieve network-wide “One Ticket” interconnection. This allows passengers to use Tianjin Metro special discount cards, all-purpose cards, Beijing-Tianjin-Hebei all-purpose cards, or internet app QR codes and face-scan gate access smoothly on the Z4 Line.

Such complex interconnection demands place extremely high requirements on the underlying data processing capability: the system must process massive transaction data from 24 stations in real time and ensure millisecond-level data synchronization with the clearing center and payment platforms.

Three-Tier Support: GBase Strengthens the Data Foundation of Z4 Line

Beitang Station

To meet the high demands, GBase provides end-to-end data support for Z4 Line, from station to center, from migration to operation and maintenance.

  • Station Level: Each day, hundreds of thousands of inbound and outbound transactions at Z4 Line stations are synchronized in real time to the center via the HAC metropolitan replication mechanism, ensuring no transaction record is lost or miscounted whether by card or QR scan.

  • Center Level: Data from all 24 stations converge at the center, where the SSC cluster processes clearing and settlement in parallel with multiple nodes, and combined with HAC disaster recovery enables second-level failover, guaranteeing 24/7 interruption-free passenger flow analysis and revenue accounting.

  • Toolchain: The RTSync real-time synchronization tool offers millisecond-level data sync capability, which can strongly support future data exchange between the Z4 Line AFC system and platforms like Tianjin ACC and Binhai MLC, facilitating real-time synchronization of ticketing transactions and passenger flow information to ensure accuracy and efficiency of line-network clearing and settlement.

Currently, GBase is widely used in AFC systems, clearing centers, multi-line centers, internet ticketing platforms, integrated monitoring systems, and operation command centers across multiple metro lines. Its embedded version further enables lightweight and flexible deployment for on-board systems.

Extreme Verification: Integration Tests Deliver Satisfactory Results

Aircraft Carrier Park Station

During the integration testing phase, the system integrator organized three ACC-level system tests, each lasting over 4 hours, with simulated passenger flow exceeding 10,000 per hour per station—equivalent to stressing a station at peak capacity for 4 consecutive hours.

How did GBase perform? The system responded smoothly, transaction data was accurate and error-free, achieving a flawless pass. It proved its reliability and stability in ultra-large-scale rail transit scenarios with solid performance.

The successful launch of Tianjin’s Z4 Line once again demonstrates GBase’s exceptional capability in critical rail transit infrastructure: building a solid data foundation to support every smooth journey, and harnessing the power of data to make city operations smarter and more efficient.