high performance Nim - the first high performance language with full support for hot code- language with full support for hot code- reloading at runtime reloading at runtime by Viktor Kirilov 1 Me, myself the performant programming language landscape read: heavily biased C++ rant Nim compilation model hot code reloading usage & implementation ".dll" => assume .so/.dylib (platform-agnostic) demo comments shared libraries OR hot-patching: possible for decades - but not widely used usually quite intrusive (interfaces, constraints, complicated setup) in game engines: Unreal, others... hot-patching (with very

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

overprovisioned resources Merge shards and/or keyspaces Increase geo-diversity Add new cells and replicas Cool a hot tablet For read access, add replicas or split shards. For write access, split shards. Additional Tools if empty, no tracing will be done db-credentials-file string db credentials file; send SIGHUP to reload this file db-credentials-server string db credentials server type (use ‘file’ for the file implementation) ng string JSON representation of the users/passwords config. mysql_auth_static_reload_interval duration Ticker to reload credentials mysql_clientcert_auth_method string client-side authentication method

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

overprovisioned resources Merge shards and/or keyspaces Increase geo-diversity Add new cells and replicas Cool a hot tablet For read access, add replicas or split shards. For write access, split shards. Additional Tools if empty, no tracing will be done db-credentials-file string db credentials file; send SIGHUP to reload this file db-credentials-server string db credentials server type (use ‘file’ for the file implementation) ng string JSON representation of the users/passwords config. mysql_auth_static_reload_interval duration Ticker to reload credentials mysql_clientcert_auth_method string client-side authentication method

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

2. Say, a DDL is applied 3. The watcher vstream sees the DDL and 1. asks the schema engine to reload the schema, also providing the corresponding gtid position 2. notifies the tracker of a schema change # enable_hot_row_protection , enable_hot_row_protection_dry_run # Default value is same as txPool.size. maxQueueSize: 20 # hot_row_protection_max_queue_size maxGlobalQueueSize: 1000 # hot_row_protec hot_row_protection_max_global_queue_size maxConcurrency: 5 # hot_row_protection_concurrent_transactions consolidator: enable|disable|notOnMaster # enable-consolidator , enable-consolidator -replicas heartbeatIntervalMilliseconds: