Shenyang Metro ANCC System Construction Project

The ANCC (AFC Clearing Center) system of Shenyang Metro serves as the sole clearing and settlement center for the metro network, supporting the construction and operation of the AFC system across all lines and accommodating the connection of all lines in the long-term plan. The production system demands high reliability and requires two centers—primary and secondary—connected via fiber-optic links. The primary and secondary centers must achieve active-active operation for both business and applications, with real-time data synchronization between them. In the event of partial or complete server failure at either center, business and applications must continue uninterrupted without data loss.

Topology Diagram of Shenyang Metro Project

The ANCC is planned to be deployed concurrently with the Line 4 project. The hardware is provisionally configured to accommodate seven existing lines (1, 2, 9, 10, 4, 3, 6) and three extensions (Eastern Extension of Line 1, Southern Extension of Line 2, Phase 2 of Line 9), while considering an 8-year design lifespan for computing and network equipment—this configuration can be adjusted based on the design life and specific line access requirements. The system reserves capacity for future line expansions and system scaling. As subsequent metro lines are constructed, they will be integrated into this clearing center system, which will be responsible for the operation and management of AFC systems across the entire network, internal clearing, and settlement with the "Shengjing Card" system.

• Database Architecture

To meet the high‑availability requirements of enterprise core business systems, the project is built on GBase 8s database from General Data Technology Co., Ltd. Leveraging the robust clustering capabilities and high reliability of GBase 8s standalone operation, the solution combines Shared Storage Cluster (SSC) and High‑performance Availability Cluster (HAC) to create an active‑active high‑availability architecture. Data synchronization for the historical databases between the primary and standby centers is handled by storage array replication, achieving the active‑active goal. After thorough testing—including comprehensive application compatibility, connectivity, destructive failover, stability, and performance verification—the system was officially launched.

• Advantages of GBase 8s High‑Availability Architecture

SSC Architecture: Multiple nodes can access shared storage simultaneously; in‑memory synchronization between nodes is achieved through LSN transmission; secondary nodes support read and write operations (with the final write step routed to the primary node); secondary nodes can be dynamically added or removed, scaling up to 128 nodes; workloads are balanced across nodes, enabling read/write separation.

HAC Architecture: Provides database‑instance‑level data replication; standby servers support read and write operations, enabling read/write separation; suitable for intra‑data‑center high availability or intra‑city disaster recovery; flexible modes can be configured according to the required RPO: fully synchronous mode, asynchronous mode, or a compromise mode.

Since going live, the GBase 8s database has remained stable and highly available, fully meeting business demands.

The system is designed to support a daily passenger flow of approximately 3 million by 2025, achieving a processing capacity of around 7.5 million transactions per day.

By 2032, it is projected to handle a daily passenger flow of about 5 million, with a daily transaction volume of roughly 12.5 million. By 2047, the system is expected to accommodate a daily passenger flow of about 9 million and reach a processing capacity of approximately 22.5 million transactions per day.