Tune TiFlash Performance
This document introduces how to tune the performance of TiFlash, including planning machine resources and tuning TiDB parameters.
Plan resources
If you want to save machine resources and have no requirement on isolation, you can use the method that combines the deployment of both TiKV and TiFlash. It is recommended that you save enough resources for TiKV and TiFlash respectively, and do not share disks.
Tune TiDB parameters
For the TiDB node dedicated to OLAP/TiFlash, it is recommended that you increase the value of the
tidb_distsql_scan_concurrency
configuration item for this node to80
:set @@tidb_distsql_scan_concurrency = 80;
Enable the optimization for TiDB Operator such as the aggregate pushdown of
JOIN
orUNION
:set @@tidb_opt_agg_push_down = 1;