PolarDB安装
1、关闭透明大页
cat /sys/kernel/mm/transparent_hugepage/enabled
如返回结果为always madvise never则表示已关闭透明大页。
否则执行以下操作以关闭透明大页。
echo never > /sys/kernel/mm/transparent_hugepage/enabled
2、安装主程序
root@standby PolarDB# yum -y install t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64.rpm
Loaded plugins: ulninfo
Examining t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64.rpm: t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64
Marking t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package t-polardbx-engine.x86_64 0:8.4.19-20250825_17558853.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=====================================================================================================================================================================================
Package Arch Version Repository Size
=====================================================================================================================================================================================
Installing:
t-polardbx-engine x86_64 8.4.19-20250825_17558853.el7 /t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64 2.8 G
Transaction Summary
=====================================================================================================================================================================================
Install 1 Package
Total size: 2.8 G
Installed size: 2.8 G
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64 1/1
Copying /u01/xcluster80_20250825_current to /u01/xcluster80
Copying /u01/xcluster80_20250825_current to /u01/xcluster80_20250825
Verifying : t-polardbx-engine-8.4.19-20250825_17558853.el7.x86_64 1/1
Installed:
t-polardbx-engine.x86_64 0:8.4.19-20250825_17558853.el7
Complete!
注：安装完成后，默认会创建/u01/目录，可以在u01目录下看到对应的数据库二进制文件，如下。
root@standby PolarDB# cd /u01/
root@standby u01# ll
drwxr-xr-x 11 root root 4096 Apr 14 11:59 xcluster80
drwxr-xr-x 11 root root 4096 Apr 14 11:59 xcluster80_20250825
3、创建并切换到 polardbx 用户
useradd -ms /bin/bash polardbx
echo "polardbx:polardbx" | chpasswd
echo "polardbx ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
su - polardbx
4、配置初始化参数
确认当前操作系统用户是 polardbx 用户，而不是 root 用户。
准备文件目录：
mkdir polardbx-engine
cd polardbx-engine && mkdir log mysql run data tmp
准备配置文件（/home/polardbx/polardbx-engine/my.cnf），创建文件 touch my.cnf，并粘贴如下文本：
$ cat my.cnf
mysqld
basedir = /u01/xcluster80
datadir = /home/polardbx/polardbx-engine/data
tmpdir = /home/polardbx/polardbx-engine/tmp
socket = /home/polardbx/polardbx-engine/tmp/mysql.sock
log_error = /home/polardbx/polardbx-engine/log/alert.log
port = 4886
default_authentication_plugin = mysql_native_password
lower_case_table_names = 1
gtid_mode = ON
enforce_gtid_consistency = ON
log_bin = 1
sync_binlog=1
innodb_flush_log_at_trx_commit=1
log_error_verbosity = 3
mysqlx=0
enable_polarx_rpc=0
loose-mysqlx-ssl=DISABLED
ssl=0
cluster_id = 1749112302
cluster_info = 192.168.142.14:14886@1
server_id = 1001
mysqld_safe
pid_file = /home/polardbx/polardbx-engine/run/mysql.pid
5、初始化数据文件
初始化
/u01/xcluster80/bin/mysqld --defaults-file=my.cnf --initialize-insecure
检查初始化是否成功
ls -al data/* | grep lizard
...
-rw-r----- 1 polardbx polardbx 12582912 Apr 14 12:50 lizard.ibd
...
初始化正常后，可以启动或停止（以下命令使用的路径均为相对路径，请在 /home/polardbx/polardbx-engine 目录或实际 my.cnf 所在目录下执行，否则请将所有相对路径替换为绝对路径）。
启动
/u01/xcluster80/bin/mysqld_safe --defaults-file=my.cnf &
可以检查日志输出是否正常
tail -n 200 log/alert.log
停止，通过mysqladmin触发mysqld_safe和mysqld停止
/u01/xcluster80/bin/mysqladmin --defaults-file=my.cnf --socket=tmp/mysql.sock -p shutdown
6、登录数据库，验证状态（单节点启动，本机就是leader）
/u01/xcluster80/bin/mysql -h127.0.0.1 -P4886 -uroot
查询本机的paxos角色
mysql> SELECT * FROM INFORMATION_SCHEMA.ALISQL_CLUSTER_LOCAL \G
*************************** 1. row ***************************
SERVER_ID: 1
CURRENT_TERM: 2
CURRENT_LEADER: 192.168.142.14:14886
COMMIT_INDEX: 1
LAST_LOG_TERM: 2
LAST_LOG_INDEX: 1
ROLE: Leader
VOTED_FOR: 1
LAST_APPLY_INDEX: 1
SERVER_READY_FOR_RW: Yes
INSTANCE_TYPE: Normal
DISABLE_ELECTION: No
APPLY_RUNNING: No
LEADER_IP:
LEADER_PORT: 0
1 row in set (0.00 sec)
查询集群所有机器的paxos角色
mysql> SELECT * FROM INFORMATION_SCHEMA.ALISQL_CLUSTER_GLOBAL \G
*************************** 1. row ***************************
SERVER_ID: 1
IP_PORT: 192.168.142.14:14886
MATCH_INDEX: 1
NEXT_INDEX: 0
ROLE: Leader
HAS_VOTED: Yes
FORCE_SYNC: No
ELECTION_WEIGHT: 5
LEARNER_SOURCE: 0
APPLIED_INDEX: 1
PIPELINING: No
SEND_APPLIED: No
INSTANCE_TYPE: Normal
DISABLE_ELECTION: No
SERVER_IP:
SERVER_PORT: 0
1 row in set (0.00 sec)