# TiDB 集群的扩展与缩减 ## 概述 TiDB采用分布式架构，将计算（SQL层）和存储（TiKV层）分离，便于水平扩展。无需对应用程序造成大规模停机或中断，即可在TiDB集群中添加或删除节点，以调整容量和性能。 ![56%](https://lab-static.pingcap.com/quick-demo/demo_009_en.png) ### 实验时长 + 完成此练习大约需要 60 分钟。 ### 任务 + 使用`sysbench`施加测试负载。 + 在Grafana仪表盘中观察TiDB的性能指标。 + 水平扩展TiDB的SQL层。 + 水平扩展TiDB的存储层。 > [!TIP] > 点击 **开始** 启动实验环境。 > 环境准备就绪后，点击底部工具栏中的 **前进** 进入 **模块 1**。 > 然后，按照实验指南的步骤连接到实践环境并开始你的任务。 ## 模块 1: 检查并设置环境 ### 步骤 1. 连接至 TiUP 控制机 + 点击这里 - [终端 1](ssh://monitor1-ssh#1) 打开一个新的终端，连接到为你的实践实验分配的虚拟机。 + 登录后显示的横幅： ```output , #_ ~\_ ####_ Amazon Linux 2 ~~ \_#####\ ~~ \###| ~~ \#/ ___ ~~ V~' '-> ~~~ / A newer version of Amazon Linux is available! ~~._. _/ _/ _/ Amazon Linux 2023, GA and supported until 2028-03-15. _/m/' https://aws.amazon.com/linux/amazon-linux-2023/ ``` ### 步骤 2. 确认 TiDB 集群状态 + 通过TiProxy观察集群运行状态，其中包括一个`tidb`服务器和三个`tikv`服务器。 ```bash ~/.tiup/bin/tiup cluster display tidb-demo ``` ```output Cluster type: tidb Cluster name: tidb-demo Cluster version: v8.1.0 Deploy user: ec2-user SSH type: builtin Dashboard URL: http://35.91.126.63:2379/dashboard Grafana URL: http://10.90.4.204:3000 ID Role Host Ports OS/Arch Status Data Dir Deploy Dir -- ---- ---- ----- ------- ------ -------- ---------- 10.90.4.204:9093 alertmanager 10.90.4.204 9093/9094 linux/x86_64 Up /tidb-data/alertmanager-9093 /tidb-deploy/alertmanager-9093 10.90.4.204:3000 grafana 10.90.4.204 3000 linux/x86_64 Up - /tidb-deploy/grafana-3000 10.90.3.89:2379 pd 10.90.3.89 2379/2380 linux/x86_64 Up|L /tidb-data/pd-2379 /tidb-deploy/pd-2379 10.90.4.204:9090 prometheus 10.90.4.204 9090/12020 linux/x86_64 Up /tidb-data/prometheus-9090 /tidb-deploy/prometheus-9090 10.90.1.74:4000 tidb 10.90.1.74 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.1.103:20160 tikv 10.90.1.103 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.1.30:20160 tikv 10.90.1.30 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.1.34:20160 tikv 10.90.1.34 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.4.204:6000 tiproxy 10.90.4.204 6000/3080 linux/x86_64 Up - /tidb-deploy/tiproxy-6000 Total nodes: 9 ``` ### 步骤 3. 创建 sysbench 配置 ```bash cat << EOF > sysbench_config mysql-host=${HOST_MONITOR1_PRIVATE_IP} mysql-port=6000 mysql-user=root mysql-password= mysql-db=sbtest time=120 threads=14 report-interval=5 EOF cat sysbench_config ``` ```output mysql-host=10.90.4.204 mysql-port=6000 mysql-user=root mysql-password= mysql-db=sbtest time=120 threads=14 report-interval=5 ``` ### 步骤 4. 连接TiDB集群并创建空数据库 `sbtest` ```bash mysql -h ${HOST_MONITOR1_PRIVATE_IP} -P 6000 -uroot ``` ```output Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 0 Server version: 8.0.11-TiDB-v8.1.0 TiDB Server (Apache License 2.0) Community Edition, MySQL 8.0 compatible Copyright (c) 2000, 2023, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> ``` ```sql CREATE DATABASE sbtest; EXIT; ``` ```output Query OK, 0 rows affected (0.11 sec) Bye ``` ### 步骤 5. 准备数据 + 准备`sysbench`数据，需约3分钟完成。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 prepare ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Initializing worker threads... Creating table 'sbtest4'... Creating table 'sbtest1'... Creating table 'sbtest3'... Creating table 'sbtest2'... Creating table 'sbtest6'... Creating table 'sbtest5'... Inserting 1000000 records into 'sbtest6' Inserting 1000000 records into 'sbtest5' Inserting 1000000 records into 'sbtest4' Inserting 1000000 records into 'sbtest3' Inserting 1000000 records into 'sbtest1' Inserting 1000000 records into 'sbtest2' Creating a secondary index on 'sbtest6'... Creating a secondary index on 'sbtest1'... Creating a secondary index on 'sbtest4'... Creating a secondary index on 'sbtest2'... Creating a secondary index on 'sbtest5'... Creating a secondary index on 'sbtest3'... ``` ## 模块 2: 执行工作负载并观察基线 ### 步骤 1. 执行测试工作负载 + 运行`sysbench`测试工作负载，需2分钟完成。随后在Grafana仪表板中观察`TiDB CPU`指标。默认登陆用户名和密码均为`admin`。 + 开始`sysbench`工作负载。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 run ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Running the test with following options: Number of threads: 14 Report intermediate results every 5 second(s) Initializing random number generator from current time Initializing worker threads... Threads started! [ 5s ] thds: 14 tps: 1106.04 qps: 17712.85 (r/w/o: 15498.17/0.00/2214.68) lat (ms,95%): 14.73 err/s: 0.00 reconn/s: 0.00 [ 10s ] thds: 14 tps: 1134.45 qps: 18164.46 (r/w/o: 15895.35/0.00/2269.11) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 15s ] thds: 14 tps: 1127.79 qps: 18036.91 (r/w/o: 15781.72/0.00/2255.19) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 20s ] thds: 14 tps: 1123.20 qps: 17972.54 (r/w/o: 15725.75/0.00/2246.79) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 25s ] thds: 14 tps: 1118.78 qps: 17901.07 (r/w/o: 15663.52/0.00/2237.56) lat (ms,95%): 14.46 err/s: 0.00 reconn/s: 0.00 [ 30s ] thds: 14 tps: 1121.02 qps: 17935.94 (r/w/o: 15693.90/0.00/2242.04) lat (ms,95%): 14.73 err/s: 0.00 reconn/s: 0.00 [ 35s ] thds: 14 tps: 1121.80 qps: 17946.19 (r/w/o: 15702.99/0.00/2243.20) lat (ms,95%): 14.46 err/s: 0.00 reconn/s: 0.00 [ 40s ] thds: 14 tps: 1132.40 qps: 18117.60 (r/w/o: 15852.60/0.00/2265.00) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 45s ] thds: 14 tps: 1125.60 qps: 18013.78 (r/w/o: 15762.38/0.00/2251.40) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 50s ] thds: 14 tps: 1127.81 qps: 18038.28 (r/w/o: 15782.87/0.00/2255.41) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 55s ] thds: 14 tps: 1138.60 qps: 18227.42 (r/w/o: 15950.02/0.00/2277.40) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 60s ] thds: 14 tps: 1132.79 qps: 18117.01 (r/w/o: 15851.64/0.00/2265.38) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 65s ] thds: 14 tps: 1125.40 qps: 18010.87 (r/w/o: 15760.06/0.00/2250.81) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 70s ] thds: 14 tps: 1129.00 qps: 18057.99 (r/w/o: 15799.99/0.00/2258.00) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 75s ] thds: 14 tps: 1121.60 qps: 17951.22 (r/w/o: 15708.02/0.00/2243.20) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 80s ] thds: 14 tps: 1127.20 qps: 18032.66 (r/w/o: 15778.25/0.00/2254.41) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 85s ] thds: 14 tps: 1127.99 qps: 18047.72 (r/w/o: 15791.93/0.00/2255.79) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 90s ] thds: 14 tps: 1124.00 qps: 17982.04 (r/w/o: 15733.83/0.00/2248.20) lat (ms,95%): 14.46 err/s: 0.00 reconn/s: 0.00 [ 95s ] thds: 14 tps: 1131.20 qps: 18100.34 (r/w/o: 15837.94/0.00/2262.39) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 100s ] thds: 14 tps: 1133.19 qps: 18137.49 (r/w/o: 15870.90/0.00/2266.59) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 105s ] thds: 14 tps: 1132.61 qps: 18120.69 (r/w/o: 15855.48/0.00/2265.21) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 110s ] thds: 14 tps: 1127.39 qps: 18036.31 (r/w/o: 15781.72/0.00/2254.59) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 115s ] thds: 14 tps: 1121.41 qps: 17944.32 (r/w/o: 15701.70/0.00/2242.61) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 120s ] thds: 14 tps: 1126.40 qps: 18023.22 (r/w/o: 15770.02/0.00/2253.20) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 SQL statistics: queries performed: read: 1892856 write: 0 other: 270408 total: 2163264 transactions: 135204 (1126.59 per sec.) queries: 2163264 (18025.46 per sec.) ignored errors: 0 (0.00 per sec.) reconnects: 0 (0.00 per sec.) General statistics: total time: 120.0103s total number of events: 135204 Latency (ms): min: 9.71 avg: 12.42 max: 226.04 95th percentile: 14.21 sum: 1679909.05 Threads fairness: events (avg/stddev): 9657.4286/184.44 execution time (avg/stddev): 119.9935/0.00 ``` ### 步骤 2. 观察基线 + 登录Grafana仪表盘，进入`Home`，然后选择`tidb-demo`，接着选择`tidb-demo-Performance-Overview`。在`Performance Overview`下，向下滚动至`TiDB CPU`面板，注意观察由`sysbench`工作负载产生的指标。 ![56](https://lab-static.pingcap.com/quick-demo/demo-009-status-01.png) ## 模块 3: 扩展 SQL 层 + 在集群中添加一个TiDB服务器，扩展SQL层。重新执行相同的工作负载，比较`TiDB CPU`消耗，与之前的步骤相比，观察其比例降低。 ### 步骤 1. 检查 TiDB 服务器的扩展设置 ```bash cat scale-out-tidb.yaml ``` ```output tidb_servers: - host: 10.90.1.48 port: 4000 status_port: 10080 deploy_dir: /tidb-deploy/tidb-4000 log_dir: /tidb-deploy/tidb-4000/log ``` ### 步骤 2. 添加一个 TiDB 服务器到现有集群 ```bash ~/.tiup/bin/tiup cluster scale-out tidb-demo scale-out-tidb.yaml --user ec2-user -i ~/.ssh/pe-class-key-oregon.pem -y ``` ```output ... Scaled cluster `tidb-demo` out successfully ``` ### 步骤 3. 确认 TiDB 集群状态 + 确保 TiDB 集群中有两个`tidb`服务器。SQL 层的规模从1扩展至2。 ```bash ~/.tiup/bin/tiup cluster display tidb-demo ``` ```output Cluster type: tidb Cluster name: tidb-demo Cluster version: v8.1.0 Deploy user: ec2-user SSH type: builtin Dashboard URL: http://54.148.94.44:2379/dashboard Grafana URL: http://10.90.4.172:3000 ID Role Host Ports OS/Arch Status Data Dir Deploy Dir -- ---- ---- ----- ------- ------ -------- ---------- 10.90.4.172:9093 alertmanager 10.90.4.172 9093/9094 linux/x86_64 Up /tidb-data/alertmanager-9093 /tidb-deploy/alertmanager-9093 10.90.4.172:3000 grafana 10.90.4.172 3000 linux/x86_64 Up - /tidb-deploy/grafana-3000 10.90.3.139:2379 pd 10.90.3.139 2379/2380 linux/x86_64 Up|L /tidb-data/pd-2379 /tidb-deploy/pd-2379 10.90.4.172:9090 prometheus 10.90.4.172 9090/12020 linux/x86_64 Up /tidb-data/prometheus-9090 /tidb-deploy/prometheus-9090 10.90.2.230:4000 tidb 10.90.2.230 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.2.75:4000 tidb 10.90.2.75 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.3.102:20160 tikv 10.90.3.102 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.171:20160 tikv 10.90.3.171 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.56:20160 tikv 10.90.3.56 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.4.172:6000 tiproxy 10.90.4.172 6000/3080 linux/x86_64 Up - /tidb-deploy/tiproxy-6000 Total nodes: 10 ``` ### 步骤 4. 重新执行相同的`sysbench`测试工作负载，需2分钟完成。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 run ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Running the test with following options: Number of threads: 14 Report intermediate results every 5 second(s) Initializing random number generator from current time Initializing worker threads... Threads started! [ 5s ] thds: 14 tps: 1138.22 qps: 18237.17 (r/w/o: 15958.53/0.00/2278.65) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 10s ] thds: 14 tps: 1128.66 qps: 18053.90 (r/w/o: 15796.19/0.00/2257.71) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 15s ] thds: 14 tps: 1146.20 qps: 18341.64 (r/w/o: 16049.03/0.00/2292.60) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 20s ] thds: 14 tps: 1133.40 qps: 18125.81 (r/w/o: 15859.41/0.00/2266.40) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 25s ] thds: 14 tps: 1142.40 qps: 18288.81 (r/w/o: 16004.01/0.00/2284.80) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 30s ] thds: 14 tps: 1138.60 qps: 18210.79 (r/w/o: 15933.19/0.00/2277.60) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 35s ] thds: 14 tps: 1147.39 qps: 18363.10 (r/w/o: 16068.31/0.00/2294.79) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 40s ] thds: 14 tps: 1138.80 qps: 18220.87 (r/w/o: 15943.26/0.00/2277.61) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 45s ] thds: 14 tps: 1137.80 qps: 18204.20 (r/w/o: 15928.80/0.00/2275.40) lat (ms,95%): 14.21 err/s: 0.00 reconn/s: 0.00 [ 50s ] thds: 14 tps: 1149.21 qps: 18380.90 (r/w/o: 16082.68/0.00/2298.21) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 55s ] thds: 14 tps: 1138.80 qps: 18227.03 (r/w/o: 15949.23/0.00/2277.80) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 60s ] thds: 14 tps: 1144.20 qps: 18305.17 (r/w/o: 16016.77/0.00/2288.40) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 65s ] thds: 14 tps: 1150.61 qps: 18409.75 (r/w/o: 16108.93/0.00/2300.82) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 70s ] thds: 14 tps: 1146.38 qps: 18348.26 (r/w/o: 16054.91/0.00/2293.36) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 75s ] thds: 14 tps: 1146.61 qps: 18336.94 (r/w/o: 16043.92/0.00/2293.02) lat (ms,95%): 13.70 err/s: 0.00 reconn/s: 0.00 [ 80s ] thds: 14 tps: 1140.80 qps: 18264.44 (r/w/o: 15982.63/0.00/2281.80) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 85s ] thds: 14 tps: 1140.60 qps: 18242.54 (r/w/o: 15961.55/0.00/2280.99) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 90s ] thds: 14 tps: 1141.40 qps: 18260.07 (r/w/o: 15977.06/0.00/2283.01) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 95s ] thds: 14 tps: 1148.80 qps: 18390.78 (r/w/o: 16093.18/0.00/2297.60) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 100s ] thds: 14 tps: 1136.80 qps: 18181.97 (r/w/o: 15908.38/0.00/2273.60) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 105s ] thds: 14 tps: 1146.60 qps: 18341.07 (r/w/o: 16048.46/0.00/2292.61) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 110s ] thds: 14 tps: 1142.60 qps: 18286.77 (r/w/o: 16001.37/0.00/2285.40) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 [ 115s ] thds: 14 tps: 1145.40 qps: 18321.19 (r/w/o: 16030.00/0.00/2291.20) lat (ms,95%): 13.70 err/s: 0.00 reconn/s: 0.00 [ 120s ] thds: 14 tps: 1147.79 qps: 18365.31 (r/w/o: 16069.92/0.00/2295.39) lat (ms,95%): 13.95 err/s: 0.00 reconn/s: 0.00 SQL statistics: queries performed: read: 1919484 write: 0 other: 274212 total: 2193696 transactions: 137106 (1142.42 per sec.) queries: 2193696 (18278.68 per sec.) ignored errors: 0 (0.00 per sec.) reconnects: 0 (0.00 per sec.) General statistics: total time: 120.0126s total number of events: 137106 Latency (ms): min: 9.26 avg: 12.25 max: 224.92 95th percentile: 13.95 sum: 1679939.18 Threads fairness: events (avg/stddev): 9793.2857/474.34 execution time (avg/stddev): 119.9957/0.00 ``` ### 步骤 5. 观察改变的指标 + 再次从Grafana仪表板观察`TiDB CPU`指标，并点击面板中的`avg`角标。因为SQL层现在有两个`tidb`服务器，所以与先前的步骤相比，平均`TiDB CPU`消耗比例相应减少，单个`tidb`服务器的平均CPU消耗减至配置前的50%。 ![56](https://lab-static.pingcap.com/quick-demo/demo-009-status-02.png) ## 模块 4: 扩展存储层 + 在执行`sysbench`工作负载时对存储层进行扩展。 ### 步骤 1. 打开新的终端窗口(Terminal 2)，并登陆至 monitor1_address + 点击这里 - [终端 2](ssh://monitor1-ssh#2) 打开一个新的终端，连接到为你的实践实验分配的虚拟机。 + 登录后显示的横幅： ```output , #_ ~\_ ####_ Amazon Linux 2 ~~ \_#####\ ~~ \###| ~~ \#/ ___ ~~ V~' '-> ~~~ / A newer version of Amazon Linux is available! ~~._. _/ _/ _/ Amazon Linux 2023, GA and supported until 2028-03-15. _/m/' https://aws.amazon.com/linux/amazon-linux-2023/ ``` ### 步骤 2. 执行测试工作负载 + [终端 2](ssh://monitor1-ssh#2) 中，执行`sysbench`工作负载。在此过程中无需等待完成，继续执行接下来的步骤。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 run ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Running the test with following options: Number of threads: 14 Report intermediate results every 5 second(s) Initializing random number generator from current time Initializing worker threads... Threads started! ... ``` ### 步骤 3. 添加一个TiKV服务器到集群 + 返回[终端 1](ssh://monitor1-ssh#1)，扩展存储层，添加一个TiKV服务器。 ```bash cat scale-out-tikv.yaml ``` ```output tikv_servers: - host: 10.90.1.245 port: 20160 status_port: 20180 ``` ```bash ~/.tiup/bin/tiup cluster scale-out tidb-demo scale-out-tikv.yaml --user ec2-user -i ~/.ssh/pe-class-key-oregon.pem -y ``` ```output ... Scaled cluster `tidb-demo` out successfully ``` ### 步骤 4. 确认 TiDB 集群状态 + 确保 TiDB 集群中有四个`tikv`服务器。TiKV 层的规模从3扩展至4。 ```bash ~/.tiup/bin/tiup cluster display tidb-demo ``` ```output Cluster type: tidb Cluster name: tidb-demo Cluster version: v8.1.0 Deploy user: ec2-user SSH type: builtin Dashboard URL: http://35.91.126.63:2379/dashboard Grafana URL: http://10.90.4.204:3000 ID Role Host Ports OS/Arch Status Data Dir Deploy Dir -- ---- ---- ----- ------- ------ -------- ---------- 10.90.4.204:9093 alertmanager 10.90.4.204 9093/9094 linux/x86_64 Up /tidb-data/alertmanager-9093 /tidb-deploy/alertmanager-9093 10.90.4.204:3000 grafana 10.90.4.204 3000 linux/x86_64 Up - /tidb-deploy/grafana-3000 10.90.3.89:2379 pd 10.90.3.89 2379/2380 linux/x86_64 Up|L /tidb-data/pd-2379 /tidb-deploy/pd-2379 10.90.4.204:9090 prometheus 10.90.4.204 9090/12020 linux/x86_64 Up /tidb-data/prometheus-9090 /tidb-deploy/prometheus-9090 10.90.1.48:4000 tidb 10.90.1.48 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.1.74:4000 tidb 10.90.1.74 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.1.103:20160 tikv 10.90.1.103 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.1.245:20160 tikv 10.90.1.245 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.1.30:20160 tikv 10.90.1.30 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.1.34:20160 tikv 10.90.1.34 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.4.204:6000 tiproxy 10.90.4.204 6000/3080 linux/x86_64 Up - /tidb-deploy/tiproxy-6000 Total nodes: 11 ``` ## 模块 5: 缩减SQL层 + 在`sysbench`工作负载运行期间缩减SQL层。 ### 步骤 1. 执行测试工作负载 + 切回[终端 2](ssh://monitor1-ssh#2) 并再次执行`sysbench`工作负载。在工作负载进行时继续执行下一步操作，无需等待其完成。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 run ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Running the test with following options: Number of threads: 14 Report intermediate results every 5 second(s) Initializing random number generator from current time Initializing worker threads... Threads started! ... ``` ### 步骤 2. 从集群中删除一个 TiDB 服务器 + 在[终端 1](ssh://monitor1-ssh#1) 中，随机删除一个TiDB服务器，缩减SQL层。 ```bash RANDOM_TIDB_NODE=`~/.tiup/bin/tiup cluster display tidb-demo | grep 4000 | sed 's/ .*$//' | head -n 1` ~/.tiup/bin/tiup cluster scale-in tidb-demo --node ${RANDOM_TIDB_NODE} -y ``` ```output ... Scaled cluster `tidb-demo` in successfully ``` ### 步骤 4. 确认 TiDB 集群的状态 + 确保TiDB集群中有一个`tidb`服务器。SQL层的规模从2缩减至1。 ```bash ~/.tiup/bin/tiup cluster display tidb-demo ``` ```output Cluster type: tidb Cluster name: tidb-demo Cluster version: v8.1.0 Deploy user: ec2-user SSH type: builtin Dashboard URL: http://54.185.182.184:2379/dashboard Grafana URL: http://10.90.4.216:3000 ID Role Host Ports OS/Arch Status Data Dir Deploy Dir -- ---- ---- ----- ------- ------ -------- ---------- 10.90.4.216:9093 alertmanager 10.90.4.216 9093/9094 linux/x86_64 Up /tidb-data/alertmanager-9093 /tidb-deploy/alertmanager-9093 10.90.4.216:3000 grafana 10.90.4.216 3000 linux/x86_64 Up - /tidb-deploy/grafana-3000 10.90.3.191:2379 pd 10.90.3.191 2379/2380 linux/x86_64 Up|L /tidb-data/pd-2379 /tidb-deploy/pd-2379 10.90.4.216:9090 prometheus 10.90.4.216 9090/12020 linux/x86_64 Up /tidb-data/prometheus-9090 /tidb-deploy/prometheus-9090 10.90.1.16:4000 tidb 10.90.1.16 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.3.112:20160 tikv 10.90.3.112 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.213:20160 tikv 10.90.3.213 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.40:20160 tikv 10.90.3.40 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.71:20160 tikv 10.90.3.71 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.4.216:6000 tiproxy 10.90.4.216 6000/3080 linux/x86_64 Up - /tidb-deploy/tiproxy-6000 Total nodes: 10 ``` ## 模块 6: 缩减存储层 + 在`sysbench`工作负载进行期间缩减存储层。 ### 步骤 1. 执行测试工作负载 + 切换至[终端 2](ssh://monitor1-ssh#2)，再次执行`sysbench`工作负载。在工作负载进行期间，继续执行后续步骤，无需等待其完成。 ```bash sysbench --config-file=sysbench_config oltp_read_only --tables=6 --table-size=1000000 run ``` ```output sysbench 1.0.17 (using bundled LuaJIT 2.1.0-beta2) Running the test with following options: Number of threads: 14 Report intermediate results every 5 second(s) Initializing random number generator from current time Initializing worker threads... Threads started! ... ``` ### 步骤 2. 从集群中删除一个 TiKV 服务器 + 在[终端 1](ssh://monitor1-ssh#1) 中，随机删除一个TiKV服务器，缩减存储层。 ```bash RANDOM_TIKV_NODE=`~/.tiup/bin/tiup cluster display tidb-demo | grep 20160 | sed 's/ .*$//' | head -n 1` ~/.tiup/bin/tiup cluster scale-in tidb-demo --node ${RANDOM_TIKV_NODE} -y ``` ```output ... Scaled cluster `tidb-demo` in successfully ``` + 销毁已删除的TiKV节点。 ```bash ~/.tiup/bin/tiup cluster prune tidb-demo -y ``` ```output ... Destroy success ``` ### 步骤 3. 确认 TiDB 集群状态 + 确保TiDB集群中有三个`tikv`服务器。存储层的规模从4降至3。 ```bash ~/.tiup/bin/tiup cluster display tidb-demo ``` ```output Cluster type: tidb Cluster name: tidb-demo Cluster version: v8.1.0 Deploy user: ec2-user SSH type: builtin Dashboard URL: http://54.185.182.184:2379/dashboard Grafana URL: http://10.90.4.216:3000 ID Role Host Ports OS/Arch Status Data Dir Deploy Dir -- ---- ---- ----- ------- ------ -------- ---------- 10.90.4.216:9093 alertmanager 10.90.4.216 9093/9094 linux/x86_64 Up /tidb-data/alertmanager-9093 /tidb-deploy/alertmanager-9093 10.90.4.216:3000 grafana 10.90.4.216 3000 linux/x86_64 Up - /tidb-deploy/grafana-3000 10.90.3.191:2379 pd 10.90.3.191 2379/2380 linux/x86_64 Up|L /tidb-data/pd-2379 /tidb-deploy/pd-2379 10.90.4.216:9090 prometheus 10.90.4.216 9090/12020 linux/x86_64 Up /tidb-data/prometheus-9090 /tidb-deploy/prometheus-9090 10.90.1.16:4000 tidb 10.90.1.16 4000/10080 linux/x86_64 Up - /tidb-deploy/tidb-4000 10.90.3.213:20160 tikv 10.90.3.213 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.40:20160 tikv 10.90.3.40 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.3.71:20160 tikv 10.90.3.71 20160/20180 linux/x86_64 Up /tidb-data/tikv-20160 /tidb-deploy/tikv-20160 10.90.4.216:6000 tiproxy 10.90.4.216 6000/3080 linux/x86_64 Up - /tidb-deploy/tiproxy-6000 Total nodes: 9 ``` ## 结论 TiDB集群的SQL层（TiDB服务器）和存储层（TiKV服务器）可以根据需要独立进行扩展/缩减。该过程对于应用程序的操作和维护团队来说是无缝的，尤其是在TiDB集群前有负载均衡器的情况下更为有效。在我们的实验室中，TiProxy有效地承担了这一角色。在水平扩展过程中，您的应用程序会继续运行。 TiDB在计算层最大支持512个节点，每个节点可处理最多1000个并发连接。 TiDB服务器和TiKV服务器有所不同。TiDB服务器是无状态的，而TiKV服务器是有状态的。为更好地利用TiDB的伸缩性，您可以参加[TiDB培训和认证](https://tidb.io/education)提供的课程，进一步了解最佳实践。