Didi Tech

Jul 5, 2023 · Databases

Performance Optimization of ClickHouse: Identifying and Fixing High CPU Usage in BgMoveProcPool Threads

By adding a guard that skips the costly part‑scan in MergeTreePartsMover::selectPartsForMove when disk usage is below the threshold and no MoveTTL is set, Didi reduced BgMoveProcPool thread CPU consumption from about 30 % to under 4 %, halving overall node CPU load and improving ClickHouse’s PB‑scale performance.