关于数据库:TiDBv60与TiDBv512-TiKV-节点重启后-leader-平衡加速提升业务恢复速度对比测试

1.指标:

试用TiDB v5.1.2与TiDB v6.0.0 TiKV 节点重启后 leader 均衡减速，晋升业务复原速度比照

2.硬件配置:

3.拓扑文件配置

TiDBv5.1.2拓扑文件参数配置

server_configs:  pd:    replication.enable-placement-rules: true  tikv:    server.grpc-concurrency: 8    server.enable-request-batch: false    storage.scheduler-worker-pool-size: 8    raftstore.store-pool-size: 5    raftstore.apply-pool-size: 5    rocksdb.max-background-jobs: 12    raftdb.max-background-jobs: 12    rocksdb.defaultcf.compression-per-level: ["no","no","zstd","zstd","zstd","zstd","zstd"]    raftdb.defaultcf.compression-per-level: ["no","no","zstd","zstd","zstd","zstd","zstd"]    rocksdb.defaultcf.block-cache-size: 12GB    raftdb.defaultcf.block-cache-size: 2GB    rocksdb.writecf.block-cache-size: 6GB    readpool.unified.min-thread-count: 8    readpool.unified.max-thread-count: 16    readpool.storage.normal-concurrency: 12    raftdb.allow-concurrent-memtable-write: true    pessimistic-txn.pipelined: true  tidb:    prepared-plan-cache.enabled: true    tikv-client.max-batch-wait-time: 2000000

TiDBv6.0.0拓扑文件参数配置

只比TiDBv5.1.2拓扑文件参数配置多了storage.reserve-space: 0MB,能够疏忽这个参数的设置

server_configs:  pd:    replication.enable-placement-rules: true  tikv:    server.grpc-concurrency: 8    server.enable-request-batch: false    storage.scheduler-worker-pool-size: 8    raftstore.store-pool-size: 5    raftstore.apply-pool-size: 5    rocksdb.max-background-jobs: 12    raftdb.max-background-jobs: 12    rocksdb.defaultcf.compression-per-level: ["no","no","zstd","zstd","zstd","zstd","zstd"]    raftdb.defaultcf.compression-per-level: ["no","no","zstd","zstd","zstd","zstd","zstd"]    rocksdb.defaultcf.block-cache-size: 12GB    raftdb.defaultcf.block-cache-size: 2GB    rocksdb.writecf.block-cache-size: 6GB    readpool.unified.min-thread-count: 8    readpool.unified.max-thread-count: 16    readpool.storage.normal-concurrency: 12    raftdb.allow-concurrent-memtable-write: true    pessimistic-txn.pipelined: true    storage.reserve-space: 0MB  tidb:    prepared-plan-cache.enabled: true    tikv-client.max-batch-wait-time: 2000000

4.TiUP部署TiDBv5.1.2和TiDBv6.0.0

5.测试TiKV 节点重启后 leader 均衡工夫办法

给集群TiDBv5.1.2和TiDBv6.0.0插入不同数据(别离是100万,400万,700万,1000万),并查看TiKV 节点重启后 leader均衡工夫

sysbench oltp_common \    --threads=16 \    --rand-type=uniform \    --db-driver=mysql \    --mysql-db=sbtest \    --mysql-host=$host \    --mysql-port=$port \    --mysql-user=root \    --mysql-password=password \    prepare --tables=16 --table-size=10000000

通过以下这种形式查问表数据:

select(select count(1) from sbtest1)  "sbtest1",(select count(1) from sbtest2)  "sbtest2",(select count(1) from sbtest3)  "sbtest3",(select count(1) from sbtest4)  "sbtest4",(select count(1) from sbtest5)  "sbtest5",(select count(1) from sbtest6)  "sbtest6",(select count(1) from sbtest7)  "sbtest7",(select count(1) from sbtest8)  "sbtest8",(select count(1) from sbtest9)  "sbtest9",(select count(1) from sbtest10)  "sbtest10",(select count(1) from sbtest11)  "sbtest11",(select count(1) from sbtest12)  "sbtest12",(select count(1) from sbtest13)  "sbtest13",(select count(1) from sbtest14)  "sbtest14",(select count(1) from sbtest15)  "sbtest15",(select count(1) from sbtest16)  "sbtest16"FROM  dual

期待插入实现后,查看Grafana监控下PD->Statistics-balance->Store leader count 各个TiKV leader 均匀后,重启其中一台TiKV, 通过Grafana监控图表中Store leader count看leader均衡工夫,如下图:

注:重启能够通过systemctl stop tikv-20160.service和systemctl start tikv-20160.service模仿实现

6.测试后果

比照数据图

从表中比照数据失去:

1.大体上的确是TiDBv6.0 TiKV 节点重启后 leader 均衡减速了,比TiDBv5.1.2快了进30s。

2.从表中的数据看到:TiDBv6.0 TiKV 节点重启后,不论数据多少根本30s就实现了leader 均衡。

2.从表中也能够看到,TiDBv6.0 leader 均衡完了后,也会呈现大量leader调整,这种状况少有。

3.TiDBv6.0 TiKV敞开后,leader 均衡工夫基本上与TiDBv5.1.2没变动。

以上TiDB v5.1.2与TiDB v6.0.0 TiKV 节点重启后 leader 均衡减速, 晋升业务复原速度的比照,是没有批改balance-leader-scheduler 策略的状况下做的,能够看到默认状况下是有晋升的,如想要获取更大的减速成果,请按以下操作:

1.通过PD Control调整集群参数。

2.scheduler config balance-leader-scheduler介绍

用于查看和管制 balance-leader-scheduler 策略。

从 TiDB v6.0.0 起，PD 为 balance-leader-scheduler 引入了 Batch 参数，用于管制 balance-leader 执行工作的速度。你能够通过 pd-ctl 批改 balance-leader batch 配置项设置该性能。

在 v6.0.0 前，PD 不带有该配置（即 balance-leader batch=1）。在 v6.0.0 或更高版本中，balance-leader batch 的默认值为 4。如果你想为该配置项设置大于 4 的值，你须要同时调大 scheduler-max-waiting-operator（默认值 5）。同时调大两个配置项后，你能力体验预期的减速成果。

>> scheduler config balance-leader-scheduler set batch 3  // 将 balance-leader 调度器能够批量执行的算子大小设置为 3

参考文档:https://docs.pingcap.com/zh/t...

原文链接：https://tidb.net/blog/0cbf5031 原文作者：@ngvf