Based in Kunshan county, the first of China’s 100 most economically competitive counties, Kunshan Rural Commercial Bank (KRCB) has established the most outlets to provide the most extensive service coverage in the region. The innovative transformation of the bank has set a great example for applying the "microservice + homegrown distributed database" architecture in the banking industry.
Microservice is lately a popular architectural model, which divides a single application into a set of coordinated services. This model is highly elastic because each service is separately developed, tested, deployed, and upgraded. Features of microservice, such as the horizontal scalability and scenario-based data sharding, are what it requires for the technical innovation in the financial world.
In light of the database localization strategy, it has been a technical challenge to run microservices on a homegrown distributed database instead of using centralized cluster deployment. This is because the development and application of a database per se involve many services, let alone all the odds in ensuring data consistency among multiple services in a microservice architecture while handling the challenging cross-service data queries.
Based on TDSQL, a distributed database service developed in-house by Tencent Cloud for enterprises, the next-generation core system of KRCB has been put into operation. It adopts the "microservice + homegrown distributed database" architecture, which is applied in a regional bank for the first time.
The overall processing capacity of the new core system achieves 6,300 transactions per second (TPS), which translates into more than 100 million transactions per day. In terms of performance, the system responds to high-frequency account transactions within 300 ms and query transactions within 100 ms on average. The system can complete day-end batch processing within about 8 minutes, quarterly interest settlement within about 17 minutes, and 100,000 social security payment transactions within 96 seconds. Its performance far exceeds that of the original one and has outperformed peer banks nationwide.
The new core system is integrated with TDSQL by using Sunline V8 and incorporates technologies such as microservice, read/write separation and multi-source synchronization. In addition to guaranteed finance-grade global data consistency, the solution splits a bulky system into microservices to reduce the system complexity and implement decoupling. It breaks the bottleneck on the concurrency of conventional centralized core systems, enhances the high availability and dynamic scalability of the core system, and significantly reduces the risks and costs of system deployment, upgrade, and Ops in a secure and controlled way.
The new core system consists of three microservice clusters that run in a TDSQL cluster to handle public services, account management business, and transaction history respectively. Each microservice cluster contains a set of single-functioned but highly aggregated services, which supports flexible deployment.
The new core system is deployed in the 2-region-3-DC architecture, which features one primary database with three standby databases and strong sync across data centers. This architecture allows KRCB to achieve rapid and automatic recovery from the disaster of a data center with zero data loss.