Kernel Version Notes

This section describes the kernel version updates of DDM.

**Table 1** Kernel version description
Version	Description
3.1.2.0	New features Improve the troubleshooting capability of the connection pool, and add the fail-fast feature (disabled by default) for data nodes. Improve data verification of shard configuration. Optimize memory configuration. Support the ANALYZE TABLE statement. Rebuild global secondary index for whitelisted users.
3.1.1	New features Support global secondary index for whitelisted users. Support SSL encrypted connection.
3.1.0	New features Add filter criteria for Show Processlist and Kill Sessionid. Add keywords related to MySQL 8.0 Online DDL. Resolved issues Fixed the issue that the millisecond value is lost when UPDATE statements are executed using the DATE_SUB function. Optimized the display of field aliases in some complex queries. Fixed the issue that new tables cannot be used when rename operations are performed after other DDL operations. Fixed the error occurred when sequences are concurrently inserted.
3.0.9	New features Support the query for auto-increment progress of a sequence. Support the query for a record whose size exceeds 16 MB. Support MariaDB Connector/J. Optimize transaction splitting. If there are no updates in a transaction, requests are routed to the primary instance or a read replica based on read/write weights.
3.0.8	New features Support route calculation of ROW expressions. Support table recycle bins. Support metadata backup and restoration. Resolved issues Optimized the DDM MetaDB connection pool. Optimized the DDM process monitoring mechanism. Optimized the display of Show Processlist. Optimized the process of Reload for obtaining metadata. Optimized the process for reporting an error when a transaction rollback occurs during incremental playback.
3.0.6	New features Allow users to connect to metadata using connection pools during shard change. Resolved issues Fixed the issue that the end status of a DDL command being executed cannot be recorded when Ctrl+C is pressed. Optimized the high CPU usage when a process is killed during big data query on the client.
3.0.4	Resolved issues Fixed the error of read/write splitting in some abnormal scenarios. Optimized the execution of the GROUP_CONCAT function when there are a large amount of data.