v.24.3Improvement

Parallel Flush of Pending INSERT Blocks on DETACH and SYSTEM FLUSH DISTRIBUTED in Distributed Engine

Parallel flush of pending INSERT blocks of Distributed engine on DETACH/server shutdown and SYSTEM FLUSH DISTRIBUTED (Parallelism will work only if you have multi-disk policy for a table (like everything in the Distributed engine right now)). #60225 (Azat Khuzhin).
Introduces parallel flushing of pending INSERT blocks for the Distributed engine during DETACH, server shutdown, and SYSTEM FLUSH DISTRIBUTED commands, improving the efficiency of these operations for tables with multi-disk storage policies.

Why it matters

This feature addresses the delay caused by sequential flushing of pending data blocks in the Distributed engine, especially under multi-disk table configurations. By enabling parallel flush operations, it reduces wait times and enhances stability during server shutdowns or manual flush commands, ensuring better resource utilization and faster completion.

How to use it

To benefit from parallel flushing, ensure your Distributed table uses a multi-disk storage policy. The feature automatically applies during DETACH, server shutdown, and when executing SYSTEM FLUSH DISTRIBUTED commands without additional configuration.