Others • An interface is added between TiDB and PD. When you use the information_schema �→ .TIDB_HOT_REGIONS_HISTORY system table, TiDB needs to use PD in the corre- sponding version. • TiDB Server, d0946606d79f90025f3e09a0c1f9e81", ATTR{queue/scheduler}=" �→ noop" 6. Apply the udev script: udevadm control --reload-rules udevadm trigger --type=devices --action=change 7. Create a service to configure the CPU power WantedBy=multi-user.target EOF 8. Apply the CPU power policy configuration service: systemctl daemon-reload systemctl enable cpupower.service systemctl start cpupower.service 6. Execute the following command

cost too much CPU #4071 – Fix the data race issue that might occur when setting configurations of hot Region scheduler #4159 – Fix slow leader election caused by stucked Region syncer #3936 • TiFlash d0946606d79f90025f3e09a0c1f9e81", ATTR{queue/scheduler}=" �→ noop" 6. Apply the udev script: udevadm control --reload-rules udevadm trigger --type=devices --action=change 7. Create a service to configure the CPU power WantedBy=multi-user.target EOF 8. Apply the CPU power policy configuration service: systemctl daemon-reload systemctl enable cpupower.service systemctl start cpupower.service 6. Execute the following command

d0946606d79f90025f3e09a0c1f9e81", ATTR{queue/scheduler}=" �→ noop" 6. Apply the udev script: udevadm control --reload-rules udevadm trigger --type=devices --action=change 7. Create a service to configure the CPU power WantedBy=multi-user.target EOF 8. Apply the CPU power policy configuration service: systemctl daemon-reload systemctl enable cpupower.service systemctl start cpupower.service 6. Execute the following command The KV request duration 99 in TiKV. If you find nodes with a long duration, check whether there are hot spots, or whether there are nodes with poor performance. 6.5.1.6 PD TSO Wait Duration Figure 38:

application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.9.1.1 SQL performance tuning To get good SQL statement performance, you can follow these diagnose and resolve transaction contention, see Troubleshoot Lock Conflicts. • Hot spots. For how to diagnose and resolve hot spots, see Troubleshoot Hotspot Issues. 4.9.1.2.1 See also • SQL Performance null �→ | null | null | | 001Do000003EDTZIA4 | Edge Communications | Customer - Direct | TX �→ | Hot | Electronics | | 001Do000003EDTaIAO | Burlington Textiles Corp of America | Customer - �→ Direct

features #26333 • PD – Add more QPS dimensions for hot Region scheduling, and support adjusting the priority of the scheduling #3869 – Support hot Region balance scheduling for the write hotspot of TiFlash d0946606d79f90025f3e09a0c1f9e81", ATTR{queue/scheduler}=" �→ noop" 6. Apply the udev script: udevadm control --reload-rules udevadm trigger --type=devices --action=change 7. Create a service to configure the CPU power WantedBy=multi-user.target EOF 8. Apply the CPU power policy configuration service: systemctl daemon-reload systemctl enable cpupower.service systemctl start cpupower.service 6. Execute the following command

application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.9.1.1 SQL performance tuning To get good SQL statement performance, you can follow these diagnose and resolve transaction contention, see Troubleshoot Lock Conflicts. • Hot spots. For how to diagnose and resolve hot spots, see Troubleshoot Hotspot Issues. 4.9.1.2.1 See also • SQL Performance null �→ | null | null | | 001Do000003EDTZIA4 | Edge Communications | Customer - Direct | TX �→ | Hot | Electronics | | 001Do000003EDTaIAO | Burlington Textiles Corp of America | Customer - �→ Direct

Support setting memory usage limits for in-memory pessimistic locks in a Region or TiKV instance. When hot write scenarios cause a large number of pessimistic locks, you can increase the memory limits via configuration to scatter-range-scheduler in pd-ctl commands #8379 @okJiang • Add conflict detection for grant-hot-leader-scheduler #4903 @lhy1024 • TiFlash • Optimize the execution efficiency of LENGTH() and ASCII() application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.10.1.1 SQL performance tuning To get good SQL statement performance, you can follow these

Support setting memory usage limits for in-memory pessimistic locks in a Region or TiKV instance. When hot write scenarios cause a large number of pessimistic locks, you can increase the memory limits via configuration to scatter-range-scheduler in pd-ctl commands #8379 @okJiang • Add conflict detection for grant-hot-leader-scheduler #4903 @lhy1024 • TiFlash • Optimize the execution efficiency of LENGTH() and ASCII() application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.10.1.1 SQL performance tuning To get good SQL statement performance, you can follow these

application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.9.1.1 SQL performance tuning To get good SQL statement performance, you can follow these diagnose and resolve transaction contention, see Troubleshoot Lock Conflicts. • Hot spots. For how to diagnose and resolve hot spots, see Troubleshoot Hotspot Issues. 4.9.1.2.1 See also • SQL Performance null �→ | null | null | | 001Do000003EDTZIA4 | Edge Communications | Customer - Direct | TX �→ | Hot | Electronics | | 001Do000003EDTaIAO | Burlington Textiles Corp of America | Customer - �→ Direct

executing the reset �→ -to-version command #13829 @tabokie • PD • Fix the issue that the balance-hot-region-scheduler configuration is not per- sisted if not modified #5701 @HunDunDM • Fix the issue application workload patterns, you might need to change the table schema to avoid transaction contention or hot spots. 4.9.1.1 SQL performance tuning To get good SQL statement performance, you can follow these diagnose and resolve transaction contention, see Troubleshoot Lock Conflicts. • Hot spots. For how to diagnose and resolve hot spots, see Troubleshoot Hotspot Issues. 4.9.1.2.1 See also • SQL Performance