In recent years, influenced by the international situation, strengthening the construction of the cultural and creative industries and achieving independent and controllable core technologies has become one of the key focuses of the country. The central government has successively issued multiple documents to comprehensively drive the independent and controllable development of information systems, pressing the "acceleration key" for the high-quality development of the cultural and creative industries.

The database, as a fundamental software providing data storage and processing capabilities, is the underlying core of information systems. With the influence of international trends and the promotion of domestic policies in the past two years, the independent controllability and domestic substitution of databases have become a realistic requirement, and the development trend towards independence from imported equipment (IOE) is unstoppable.

A certain operator payment company is a state-owned enterprise under the "double-hundred reform" of the State-owned Assets Supervision and Administration Commission and the "dual pilot" enterprise under the mixed reform of the National Development and Reform Commission. It is also the only financial technology company among the "dual pilot" enterprises. The company provides payment solutions, member benefits, livelihood services, installment loans, insurance and wealth management services, relying on technologies such as blockchain, cloud computing, big data, and artificial intelligence to promote the digital upgrade of life and financial services.

As a leading enterprise in data-driven development, the telecommunications payment company began its comprehensive data migration initiative early on, transitioning to IOE.

In the past, Oracle database was the main application database for its information systems. However, in line with the trend of independent and controllable development, OceanBase has replaced Oracle as its primary application database.

OceanBase is a distributed relational database developed entirely by Ant Group and Alibaba. It features strong data consistency, high availability, high performance, online scalability, high compatibility with SQL standards and mainstream relational databases, and low cost. OceanBase has been successfully applied to all core businesses of Alipay, including transactions, payments, membership, and accounting systems, as well as Alibaba's Taobao (Tmall) favorites and P4P advertising reports. Its demonstrated product and technical advantages have made it a preferred choice for many industries today.

This operation of the payment company's information system to go O is a large-scale, comprehensive domestic database replacement, which is a crucial link to the success or failure, involving the data migration between Oracle and OceanBase databases.

To ensure the consistency of data and the security of the business system, this operation adopts a two-way backflow approach to deal with the possibility of business rollback, including the forward migration from Oracle to OceanBase and the reverse backflow from OceanBase to Oracle.

Data Migration Architecture

As a party ensuring the bidirectional migration of its data, DSG is responsible for building bidirectional synchronization queues, full migration, real-time incremental synchronization, full comparison, and real-time incremental comparison between Oracle and OceanBase, collaborating with the operator's payment company and OceanBase to achieve this large-scale domestic innovation.

This comprehensive large-scale migration has been running for some time and has successfully completed TB-level data migrations for multiple systems (including withholding systems, acquiring systems, payment systems, with the largest single table being 4.7TB in size). In the phase of leading the overall migration project, the business systems and data size of this migration are representative, and the performance data during the actual migration process is also very impressive!

In the early morning of April 25th, the operation and payment company's transaction system was successfully cut over. This transaction system cut-over involved migrating from Oracle database to the commercial version of OceanBase database, with nearly a hundred tables and a total data volume of 15-25 terabytes, with the largest table being 4.4 terabytes. The original planned downtime window was 10 minutes, but in reality, the entire cut-over process, from stopping applications to starting applications, took only 6 minutes. The cut-over process included stopping applications, checking the delay situation of the primary and standby databases, business data verification, real-time incremental comparison, closing forward synchronization, switching to reverse synchronization, and starting applications. The real-time incremental comparison process took less than 1 minute. Given the large amount of data being migrated, the speed of the entire cut-over and the efficiency of real-time incremental differential comparison were truly impressive, making us exclaim once again, "We have taken another big step forward!"

The entire data migration process involves a large amount of data, frequent changes, a high requirement for data consistency, and a short switch time. DSG needs to implement heterogeneous synchronization between Oracle and OceanBase, as well as backup and recovery from OceanBase to Oracle. Each data cut-off must ensure data consistency before the cut-off, and the downtime for each cut-off window is limited to only 10 minutes. Therefore, during the migration process, DSG adopts a method of full comparison + incremental comparison to ensure data consistency. At the same time, it uses real-time incremental comparison to compare changes in data in real time to ensure a smooth and efficient cut-off. The entire process adopts an intermediate deployment mode, which does not affect the production end.