How to address the slow data insertion into Flink streams?

There could be several reasons and solutions if Flink’s stream data loading is very slow.

1. Database connection issue: Check if the database connection is functioning properly, including checking the connection pool configuration and the database driver version. You can try using connection pooling to improve connection reuse and efficiency.
2. If the database server is experiencing high loads, it may result in slower data input. One solution could be optimizing the database configuration and adjusting hardware resources, such as increasing CPU, memory, disk, etc.
3. The database indexes need to be optimized: Check if the indexes on the database tables are reasonable and if they can accelerate query and write operations. Utilize database performance analysis tools to identify any performance bottlenecks in the database.
4. Batch writing and transaction processing: Considering using batch writing to improve write performance, you can either batch insert multiple records or use batch updating. Furthermore, using transaction processing effectively can merge multiple write operations into one transaction to reduce the number of transaction commits.
5. Data serialization and compression: Choosing the appropriate data serialization and compression methods can reduce the size of data transmission and network overhead. Flink offers a variety of serialization and compression methods to choose from.
6. Parallelism Adjustment: Adjust the parallelism of Flink jobs based on specific circumstances to increase writing performance. However, it is also important to consider the database’s capacity to handle the load.
7. Partitioning and shuffling data: Partitioning and shuffling data can reduce the load on individual tasks and improve overall write performance. This can be achieved using operations such as KeyBy and rebalance provided by Flink.

If the above methods still cannot solve the problem, further analysis and optimization of specific application scenarios and system configurations may be needed.