【新手升级必看】从 TiDB v6.5升级到 v7.5 的实践步骤

TiDB 7.5 已发布了 支持并行运行多个 ADD INDEX 语句 并且兼容MySQL 8.0. 是时候测试一下了，要测试必须先升级。那么下面就是按官方文档指示升级的过程。

升级说明：本次升级测试为测试环境，单机部署。

操作系统版本CentOS Linux release 7.8.2003 (Core)

原tidb版本 6.5.2

升级版本7.5.0

先看看官方的升级介绍：

12 月 1 日，期待已久的 TiDB v7.5.0 LTS 发版。 TiDB 7.5.0 Release Notes

作为 TiDB 7 系列的第二个长期支持版本 (LTS) ，TiDB 7.5 着眼于提升规模化场景下关键应用的稳定性。新版本中，TiDB 在可扩展性与性能、稳定性与高可用、SQL 以及可观测性等方面获得了持续的提升。TiDB 7.5 LTS 包含了已发布的 7.2.0-DMR、7.3.0-DMR 和 7.4.0-DMR 版本中的新功能、提升改进和错误修复，累计优化和修复功能 70 余项。

第一步 升级参考地址

使用 TiUP 升级 TiDB | PingCAP 文档中心

第二步 检查tiup版本

检查tiup版本

检查tiup cluster 版本

确保tiup和tiup cluster 版本不低于 1.11.3

第三步 编辑 TiUP Cluster 拓扑配置文件（可选）

注意，以下情况可跳过此步骤：

原集群没有修改过配置参数，或通过 tiup cluster 修改过参数但不需要调整。

升级后对未修改过的配置项希望使用 7.5.0 默认参数。

如果要保留就的参数配置，或者改变7.5新增的默认的参数，请修改topology 配置文件。

第四步 检查当前集群的健康状况

测试环境有一些操作系统内核参数配置不符合推荐配置。

可以通过--apply 先尝试自动修复

例如：tiup cluster check mytidb7 --cluster --apply

tiup会尝试自动修复

如果不能自动修复，需要手工修复，部分操作可能需要重启。

例如：

numactl not usable, bash: numactl: command not found numactl工具可用于查看当前服务器的NUMA节点配置、状态，可通过该工具将进程绑定到指定CPU core，由指定CPU core来运行对应进程。 FIX : yum -y install numactl.x86_64

THP is enabled, please disable it for best performance Transparent Hugepages（THP，页面内存透明化）,透明大页面（THP）是一种Linux内存管理系统，通过使用更大的内存页面，可以减少具有大量内存的计算机上的Translation Lookaside Buffer（TLB）查找的开销。但是，数据库工作负载通常在THP上表现不佳，因为它们往往具有稀疏而不是连续的内存访问模式。 您应该在Linux机器上禁用THP以确保使用***获得最佳性能。争对一些数据库，如***、MariaDB、***、VoltDB在使用时，要求关闭此功能。 FIX： vim /etc/rc.d/rc.local 1:新增： if test -f /sys/kernel/mm/transparent_hugepage/enabled; then echo never > /sys/kernel/mm/transparent_hugepage/enabled fi if test -f /sys/kernel/mm/transparent_hugepage/defrag; then echo never > /sys/kernel/mm/transparent_hugepage/defrag fi 2:授权执行： chmod +x /etc/rc.d/rc.local 3:重启： reboot

第五步 检查当前集群的 DDL 和 Backup 情况

确保无正在执行的ddl语句、无备份任务或者还原任务。

第六步 升级TiDB

tiup cluster upgrade mytidb v7.5.0

因为网络限速，多次升级失败，建议tidb延长默认的下载文件时间

第七步 升级成功输出

[root@zabbix_server ~]# tiup cluster upgrade mytidb v7.5.0 tiup is checking updates for component cluster ... A new version of cluster is available: The latest version: v1.14.0 Local installed version: v1.12.1 Update current component: tiup update cluster Update all components: tiup update --all

Starting component cluster: /root/.tiup/components/cluster/v1.12.1/tiup-cluster upgrade mytidb v7.5.0 Before the upgrade, it is recommended to read the upgrade guide at https://docs.pingcap.com/tidb/stable/upgrade-tidb-using-tiup and finish the preparation steps. This operation will upgrade tidb v6.5.2 cluster mytidb to v7.5.0. Do you want to continue? [y/N]:(default=N) y Upgrading cluster...

[ Serial ] - SSHKeySet: privateKey=/root/.tiup/storage/cluster/clusters/mytidb/ssh/id_rsa, publicKey=/root/.tiup/storage/cluster/clusters/mytidb/ssh/id_rsa.pub

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[Parallel] - UserSSH: user=tidb, host= 192.11.117.15

[ Serial ] - Download: component=tikv, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Download: component=prometheus, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Download: component=tiflash, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Download: component=pd, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Download: component=tidb, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Download: component=grafana, version=v7.5.0, os=linux, arch=amd64

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/tikv-20162

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/tiflash-9000

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/pd-2379

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/tikv-20161

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/tikv-20160

[ Serial ] - BackupComponent: component=tikv, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/tikv-20162

[ Serial ] - BackupComponent: component=tiflash, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/tiflash-9000

[ Serial ] - BackupComponent: component=pd, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/pd-2379

[ Serial ] - BackupComponent: component=tikv, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/tikv-20160

[ Serial ] - BackupComponent: component=tikv, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/tikv-20161

[ Serial ] - CopyComponent: component=tikv, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/tikv-20162 os=linux, arch=amd64

[ Serial ] - CopyComponent: component=pd, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/pd-2379 os=linux, arch=amd64

[ Serial ] - CopyComponent: component=tikv, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/tikv-20160 os=linux, arch=amd64

[ Serial ] - CopyComponent: component=tiflash, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/tiflash-9000 os=linux, arch=amd64

[ Serial ] - CopyComponent: component=tikv, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/tikv-20161 os=linux, arch=amd64

[ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/tikv-20162.service, deploy_dir=/tidb-deploy/tikv-2016 2, data_dir=[/tidb-data/tikv-20162], log_dir=/tidb-deploy/tikv-20162/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/pd-2379.service, deploy_dir=/tidb-deploy/pd-2379, dat a_dir=[/tidb-data/pd-2379], log_dir=/tidb-deploy/pd-2379/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/tikv-20160.service, deploy_dir=/tidb-deploy/tikv-2016 0, data_dir=[/tidb-data/tikv-20160], log_dir=/tidb-deploy/tikv-20160/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/tiflash-9000.service, deploy_dir=/tidb-deploy/tiflash -9000, data_dir=[/tidb-data/tiflash-9000], log_dir=/tidb-deploy/tiflash-9000/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/tikv-20161.service, deploy_dir=/tidb-deploy/tikv-2016 1, data_dir=[/tidb-data/tikv-20161], log_dir=/tidb-deploy/tikv-20161/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - Mkdir: host= 192.11.117.15, directories=

[ Serial ] - BackupComponent: component=tidb, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/tidb-4000

[ Serial ] - Mkdir: host= 192.11.117.15, directories=/tidb-data/prometheus-9090

[ Serial ] - Mkdir: host= 192.11.117.15, directories=

[ Serial ] - BackupComponent: component=grafana, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/grafana-3000

[ Serial ] - CopyComponent: component=grafana, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/grafana-3000 os=linux, arch=amd64

[ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/grafana-3000.service, deploy_dir=/tidb-deploy/grafana -3000, data_dir=[], log_dir=/tidb-deploy/grafana-3000/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - CopyComponent: component=tidb, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/tidb-4000 os=linux, arch=amd64

[ Serial ] - BackupComponent: component=prometheus, currentVersion=v6.5.2, remote= 192.11.117.15:/tidb-deploy/prometheus-9090

[ Serial ] - CopyComponent: component=prometheus, version=v7.5.0, remote= 192.11.117.15:/tidb-deploy/prometheus-9090 os=linux, arch=amd64

[ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/prometheus-9090.service, deploy_dir=/tidb-deploy/prom etheus-9090, data_dir=[/tidb-data/prometheus-9090], log_dir=/tidb-deploy/prometheus-9090/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - InitConfig: cluster=mytidb, user=tidb, host= 192.11.117.15, path=/root/.tiup/storage/cluster/clusters/mytidb/config-cache/tidb-4000.service, deploy_dir=/tidb-deploy/tidb-4000, data_dir=[], log_dir=/tidb-deploy/tidb-4000/log, cache_dir=/root/.tiup/storage/cluster/clusters/mytidb/config-cache+ [ Serial ] - UpgradeCluster Upgrading component tiflash Restarting instance 192.11.117.15:9000 Restart instance 192.11.117.15:9000 success Upgrading component pd Restarting instance 192.11.117.15:2379 Restart instance 192.11.117.15:2379 success Upgrading component tikv Restarting instance 192.11.117.15:20160 Restart instance 192.11.117.15:20160 success Evicting 1 leaders from store 192.11.117.15:20161... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Restarting instance 192.11.117.15:20161 Restart instance 192.11.117.15:20161 success Evicting 1 leaders from store 192.11.117.15:20162... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Still waitting for 1 store leaders to transfer... Restarting instance 192.11.117.15:20162 Restart instance 192.11.117.15:20162 success Upgrading component tidb Restarting instance 192.11.117.15:4000 Restart instance 192.11.117.15:4000 success Upgrading component prometheus Restarting instance 192.11.117.15:9090 Restart instance 192.11.117.15:9090 success Upgrading component grafana Restarting instance 192.11.117.15:3000 Restart instance 192.11.117.15:3000 success Stopping component node_exporter Stopping instance 192.11.117.15 Stop 192.11.117.15 success Stopping component blackbox_exporter Stopping instance 192.11.117.15 Stop 192.11.117.15 success Starting component node_exporter Starting instance 192.11.117.15 Start 192.11.117.15 success Starting component blackbox_exporter Starting instance 192.11.117.15 Start 192.11.117.15 success Upgraded cluster mytidb successfully

检查版本

结束语：

虽然是一个简单的升级，实际还是会遇到几个问题，实践大于查看。

这里把整个升级记录一下，以供参考。