maxi- mum value from 256 to 4294967295 �→ . 46 Variable name Change type Description tidb_analyze_distsql_scan_concurrency �→ Newly added Sets the concur- rency of the scan opera- tion when execut- ing response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency pd_client_cmd_handle_cmds_duration_seconds{type="wait"} + req_per_copr * ( tidb_distsql_handle_query_duration_seconds{sql_type="general"} ) tidb_distsql_handle_query_duration_seconds{sql_type="general"} <= send �→ request

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency pd_client_cmd_handle_cmds_duration_seconds{type="wait"} + req_per_copr * ( tidb_distsql_handle_query_duration_seconds{sql_type="general"} ) tidb_distsql_handle_query_duration_seconds{sql_type="general"} <= send �→ request

Region 2” TiDB TiDB TiDB Application via MySQL Protocol TiKV TiKV TiKV TiKV TiKV TiKV ... ... DistSQL API KV API PD PD PD Metadata/ Data location TSO/ Metadata TiDB architecture Pros: ● Scale-out global tidb_hashagg_partial_concurrency=16; set global tidb_projection_concurrency=4; set global tidb_distsql_scan_concurrency=20; set global tidb_index_lookup_concurrency=20; set global tidb_index_join_batch_size=25000;

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table it is recommended that you increase the value of the tidb_distsql_scan_concurrency configuration item for this node to 80: set @@tidb_distsql_scan_concurrency = 80; 2. Enable the super batch feature: 3.2 View the Grafana monitoring panel 493 In Grafana, you can see the copr-cache panel in the distsql subsystem under the tidb namespace. This panel monitors the number of hits, misses, and cache discards

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table operator that reads data. By default, this operator uses the maximum number of threads that tidb_distsql_scan_concurrency �→ allows to read data. When the memory usage of a single SQL execution exceeds it is recommended that you increase the value of the tidb_distsql_scan_concurrency configuration item for this node to 80: set @@tidb_distsql_scan_concurrency = 80; 2. Enable the super batch feature:

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency pd_client_cmd_handle_cmds_duration_seconds{type="wait"} + req_per_copr * ( tidb_distsql_handle_query_duration_seconds{sql_type="general"} ) tidb_distsql_handle_query_duration_seconds{sql_type="general"} <= send �→ request

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency pd_client_cmd_handle_cmds_duration_seconds{type="wait"} + req_per_copr * ( tidb_distsql_handle_query_duration_seconds{sql_type="general"} ) tidb_distsql_handle_query_duration_seconds{sql_type="general"} <= send �→ request

@dveeden 2.2.2.3 System variables 43 Variable name Change type Description tidb_ �→ analyze �→ _ �→ distsql �→ _ �→ scan �→ _ �→ concurrency �→ Modified Changes the mini- mum value from 1 to 0. When you set response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency

response time of the corresponding TiKV address and the Region logs in PD and KV at that time. • 7.1.5 distsql.go reports inconsistent index. The data index seems to be inconsistent. Run the admin check table memory problems caused by high concurrency. The corresponding system variables include: • tidb_distsql_scan_concurrency • tidb_index_serial_scan_concurrency • tidb_executor_concurrency • The concurrency pd_client_cmd_handle_cmds_duration_seconds{type="wait"} + req_per_copr * ( tidb_distsql_handle_query_duration_seconds{sql_type="general"} ) tidb_distsql_handle_query_duration_seconds{sql_type="general"} <= send �→ request